University of Groningen

The efficiency of voice productionSchutte, Harm Kornelis

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f •

I ; The efficiency of voice production

Rijksuniversiteit te Groningen

The efficiency of voice production

Proefschrift

ter verkrijging van het doctoraat in de Geneeskunde

aan de Rijksuniversiteit te Groningen

op gezag van de Rector Magnificus Dr. J. Borgman

in het openbaar te verdedigen op woensdag 7 mei 1980 des namiddags om 2.45 uur precies

door

Harm Kornelis Schutte geboren te Hasselt (Ov.)

Druk: Kemper/Groningen

Promotores: Prof. Dr. Jw. van den Berg Prof. Dr. P.E. Hoeksema

II

Stellingen

behorende b ij het proefschri ft The effi ci ency of voi ce p roducti on door H . K . Schu tte

Groni ngen , 7 mei 1980

1 De door Kunze geformul eerde opvatti ng dat de subql otti sche druk­meti ng met behul p van de druk in de s l okdarm vol gens de door van den Berg aangegeven methode n i et brui kbaar zou z i j n , beru s t op ver­keerde i nterpretati e van l ongfys io l ogi s che gegevens .

L . H . Kunze , Ph . D . Thes i s Iowa , 1962

2 De procedure b i j aerodynami sche meti ngen om te onderzoeken personen "vr ij te l a ten foneren" , i s acceptabel voor wat betreft de keuze van de toonhoogte , maar l e i dt tot n i et representati eve gemi ddel de waarden van s ubgl otti s che druk en fl ow al s functi e van de gel u i ds­s terkte .

3 B i j pat i enten met chroni s che l aryngi t i s of l eukopl a k i s che verande­ri ngen van de s temp l oo i en dient meer dan tot nu gebrui ke l i j k , aan­dacht besteed te worden aan de i nspann i ng waarmee de s tem geprodu­ceerd wordt . Een nauwe samenwerki ng tussen foni ate r , KNO-a rts en { kl i n i s ch ) l ogopedi s t is daartoe verei s t .

4 B i j het normal i seren van gegevens over de i ndi vi duel e s temmogel i j k­heden { fonetogram) , zoa l s door Col eman c . s . i s gedaan , gaat veel voor het i ndi v idu rel evante i n format ie verl oren .

R . F . Col eman , J . H . Mab i s en J . K . Hi nson : J Speech Hear Res , 20 , 197-204 , 1977

5 De kwal i tei t van de s tem na behandel i ng van een beperkt s templ ooi ­carci noom met de co2 l aser i s gewoonl i j k mi nder fraai dan na een rad i otherapeut i s che behandel i ng .

6 In de bedrij fsgenees kunde wordt te wei n i g aandacht besteed aan de i nv l oed van i ndustriel awaai op het gebrui k van de s tem en de daar­mee s amenhangende gezondhei dstoes tand van de l arynx .

E . Ronta l , M . Rontal , H . J . Jacob en M . I . Rol n i c k : Ann Otol Rhi nal Laryngol , 88 , 818-82 1 , 1979

7 B i j een pati ent met a fas i e moet routi nemati g een audi o l ogi sch onder­zoek pl aats vi nde n .

8 Voor een j u i s te i nd i cati estel l i ng tot het doen van een pharynxpl as­t iek b i j jonge k i nderen moet een zorgvu l d i ge afwegi ng worden ge­maa kt tussen de i nvl oed van de nog in ontwi kke l i ng z i j nde arti cul a­tie en de onvol komen werk i n g van de ve l opharyngea l e sph i ncter .

9 In het bel ang van de patient di ent een dui del i j k onders chei d ge­maakt te worden tuss en taa l ontwi kke l i ngsstoorni ssen en ges toord ge­raakte taa l functie ( afas i e ) .

S . M . Goorhui s-Brouwer , N i et-vanzel fsprekend . Ortho­v i s i e nr . 10 , Wol ters-Noordhoff 1979

10 Voor de di s cuss i e over gemeentezang : w i j ze van z i ngen , k l ankk l eur en t i mbre , tempo en verdere cu l ture l e i mpl i cati es , i s het wensel i j k dat een h i s tori s ch , eventueel metabl eti sch onderzoek gedaan wordt naar het gebrui k van de mensel i j ke stem in vroeger ti jden , in het b i j zonder ti j dens de kerkdi ensten .

1 1 De bezwaren tegen re- i mpl anta t i e van pacemakers ZlJn i n hoofdzaak gebaseerd op emoti one l e en n i et op medi s ch - techn i s che gronden .

12 De term psychogeen i n het verband " psychogene s temstoorn i s " d i ent ruim opgevat te worden , i n d i e zi n , dat met deze term wordt aange­geven dat de emoti onel e i nstel l i ng van personen de s temgeving i n h oge mate beinvl oedt , zowel b i j psych i sch gezonde , a l s psych i sch ges toorde personen .

1 3 Een psychoger' afon i e betekent vaak een i n gehouden k reet om hul p .

14 I n het al gemeen val t aan de spreektoonhoogte van co-ass i s tenten waar te nemen dat met het s t i j gen op de maatschappel i j ke l adder de gemi dde l de spreektoonhoogte daal t .

15 De st i kker achter o p auto's "Neem gas terug " kan tijdens het r i jden a l l een worden ge l ezen wanneer fl i nk gas wordt gegeven .

Acknowledgements

The fol l owi ng pe rsons , each i n thei r own way , have contri buted to my tra i n ing and the performance of th i s study . I woul d l i ke to express my appreciat ion and grati tude to a l l o f them . I thank :

P ro f . Dr . Jw . van den Berg, for h i s gui dance and advice and h i s teach i ng of voi ce phys io l ogy . I al ways wi l l remember h i s s timul ati ng personal l es sons on th i s s ubject ; Pro f . Dr . P . E . Hoeksema , Di rector of the ENT-Department . I n h i s cl i ni c I got the berth for s t udyi ng vo i ce and s peech patho logy ; M r . E . Th . Edens ( M . D . ; ENT-Surgeon ) , for h i s essenti a l contri but i on i n the di rect measuri ng of the s ubgl otti c press ure ; Mr. J . H . van Dij k , for h i s s k i l fu l effort i n prepar ing the computer programmes and i n control l i ng the computer devi ces i n the I nsti tute of Audio l ogy ; Mes s rs . P . H . C . Jongs chaap , J . A . van de Vl i e t , C . A . van Donsel aar and J . D . van Hou d t , for thei r appreci ated ass i s tance duri ng the i nvest i gati ons ; The staff of the Department of Phoni atri cs and Logopedi cs who not only acted i n thi s s tudy as tra i ned l i s teners , but a l so deserve thanks for thei r hel p i n many other ways . Mrs . S . M . Goorhui s-Brouwer for her st imu l ati ng rema rks i n our di scus s i ons on some poi nts i n the manus c ri pt ; M rs . J . M . W i l kens -Gi e tema , who not only careful l y typed several stages of the man us cri p t , but a l s o , in fact , effectuated the fi nal l ay-out ; M r . M . Gos l i nga , for h i s meti cul ous preparation of the photographs and fi gures ; Mrs . D . J . N iermeyer , for her b i b l i ographi c ass i s tance ; M r . V . J . F i dl er ( M . Sc . ) of the Centre for Medi cal Data Proces s i n g a n d Stati st i cs , for h i s advi ce on s tati sti cs ; Mes s rs . G . G . Bergi nk ( M . D . ) , and Prof . Dr . D . Graham Stua rt of the G roni ngen Un i vers i ty I nsti tute of Phoneti c Sci ences , for trans l ati ng and perus i ng the text ; The staff of the Department of Medi cal Photography { Head : Mr . J .M . �1artens ) , for ma k i ng the photographs o f the measur ing equ i pment ;

III

I V

The co-workers o f the el ectroni c workshop o f the Groni ngen Un i ve rs i ty Laboratory for Medi cal Phys i cs , Head: Mr . F . G . J . Swa rte , and E . A l b ronda , F . Berg , G . J . J . Bonga , and o f the I ns ti tute o f Aud i o l ogy , H . S . Freye , and of the techni cal servi ce of the ENT-Cl i n i c , K . Ku i tert , G . T . Pri ns , A . de Jong , for thei r va l uab le a s s i s tance ; The norma l s ubjects and the pati ents . Wi thout the i r co-operati on our i nves ti gati ons coul d not have been executed ; Al l those , whose names have not been menti oned and who a ss i sted i n short and l ong l asti ng di s cu s s i ons .

Thi s study has been el aborated i n the Ear , Nose and Throat Cl i n i c (Profess o r D r . P . E . Hoeksema ) , and the Department o f Phoni atri cs and Logopedi cs of the State Un i vers i ty Hospi tal i n Groni ngen .

The i nvesti gati o ns have been executed i n c l ose co-operation wi th the Gron i n gen Uni vers i ty Laboratory for Medi cal Phys i cs ( Professor Dr . Jw . van den Berg ) , in one o f the l aboratory rooms in the I nsti tute o f Aud i ol o gy ( P ro fessor Dr . R . J . R i tsma ) of the State Uni vers i ty Hos p i ta l i n Groni nge n .

For the tran s l ation fi nanci al s upport h a s been recei ved from the "Prof . Dr . Eel co Hu iz i nga Sti chti ng" .

We a l so gratefu l ly accepted a grant from the "Jan Dekker Sti chti ng" and the "Dr . L udgardi na Bouwman S ti chti ng" for the reproducti on of some co 1 o ured fi gures , and from the "Schol ten- Cordes Fonds " .

v

To my wife JENNY

and ow• chi ldren

VI I

I wi U sing unto the Lord as long as I live; . . .

... ; sing unto the Lor•d, aU the earth.

VI II

Psalms

104: 33a

96: lb

Contents

Chapter 1 Introduction

Chapter 2 Experimental methods

2. 1 Introduction

2.2 Pitch and intensity of phonation

2 . 2 . 1 Choi ce of pi tches and i ntens i t i es of voca 1 sounds 2 . 2 . 1 . 1 P i tch Prompter 2 . 2 . 1 . 2 Phonetogram 2 . 2 . 1 . 3 Spea k i ng voi ce pi tch 1 evel 2 . 2 . 1 . 4 Pre-sel ected pi tches

6 6 8

10 10 1 2 1 4 14

2 . 2 . 2 P i tch of the p roduced voca l sounds 15

2 . 2 . 2 . 1 Determi nation of pi tch by audi tory eva 1 uati on 16

2 . 2 . 2 . 2 I nstrumental determi nat i on of p i tch 16

2 . 2 . 3 Qual i ty of produced vocal sound 1 7

2.3 Measuring of sound intensity, total sound power 17

2 . 3 . 1 Sound i ntensi ty 1 7

2 . 3 . 2 Total sound powe r 19

2.4 Measuring of air flow rate (flow} 19

2 . 4 . 1 Des cri pti on of the pneumotachograph 20

2 . 4 . 1 . 1 Choi ce o f the fl owhead 20

2 . 4 . 1 . 2 L i nea ri ty of the pneumotachograph 21 2 . 4 . 1 . 3 Response time of the pneumotachograph 22

2 . 4 . 2 P roperti es of gases pas s i ng the fl owhead and thei r i nfl uence on flow measurement 2 . 4 . 2 . 1 Di ffe rence i n vi scos i ty of i nspi red

and expi red a i r 2 . 4 . 2 . 2 Di fference of vol ume of i nsp i red

and expi red a i r 2 . 4 . 3 Adj ustment of the pneumotachograph

2.5 Measuring of variations in pulmonary volume

22

23

24 25 26

2 . 5 . 1 Ca l i bration of fl ow and vol ume measurement 27 2 . 5 . 2 Reg i stration of vol ume curve 28

2 . 5 . 2 . 1 Course of vol ume curve due to dri ft i n fl ow ampl i fi er and/or i ntegrator 28

IX

2 . 5 . 2 . 2 Cours e of vol ume curve due to d i ffe rences i n phys i ca l properties and vol umes of i nspi red and expi red a i r 29

2.6 Measuring of oesophageal pressure 30 2 . 6 . 1 Oesophagus bal l oon catheter 3 1 2 . 6 . 2 Li neari ty o f the pressure measuri ng system 32 2 . 6 . 3 Response t ime of the press ure measur ing system 32 2 . 6 .4 Ca l i bration of the pressure measuri ng system 32

2.7 Determination of subglottic pressure 33 2 . 7 . 1 Correction for mechan i cal properti es of

the 1 ungs 35 2 . 7 . 2 Ve ri fi cati on of the i ndi rect method for

determi n ing subgl otti c pressure 40 2 . 7 . 3 Automati c correcti on for the compl i ance of

the 1 ungs 42

Chapter 3 Analysis of curves and processing of experimental data 46 3.1 Introduction 46 3.2 Rejection of curves 46 3.3 Collection of data 48 3.4 Pocessing of data. Valculation of efficiency 49 3.5 Presentation of data; regression lines 52 3.6 Comparison of data with the aid of regression lines:

characteristic values for the middle of the intensity

range 54

Chapter 4 Investigation conducted in normal subjects:

X

reference values 59 4.1 Introduction 59

4.2 Survey of the normal subjects 59 4.3 Reproducibility of phonations of a normal subject 62

4 . 3 . 1 Reproduc ib i l i ty o f phonati ons wi thi n one measuri ng seri es i n one ( s i ngl e ) s ubj ect 62

4 . 3 . 2 Regress i on l i ne for phonati ons in one measuri ng series from one s i ngl e s ubject 65

4 . 3 . 3 Regress i on l i nes o f meas uri ng series from one s ubject at d ifferent times 69 4 . 3 . 3 . 1 Di scuss ion on the res ul ts 70 4 . 3 . 3 . 2 S i gn i fi cance of E rel for the

compa rison of regress i on l i nes 72 4 . 3 . 4 Summa ry , i ntra- i nd i v i dual and i nter- i ndi vi dual

di fferences 7 3 4.4 The set of all regression lines of the normal subjects:

reference areas

4 . 4 . 1 I ntroducti on 7 5 7 5

4 . 4 . 2 The set o f al l regres s i on l i nes 75 4 . 4 . 3 Reference a reas for fl ow , subgl ottic pressure ,

and e ffi c i ency 78 4 . 4 . 4 Rejected phonations i n rel ation to the

reference a reas 4.5 Published data concerning 'normal values' compared

with data determined in this investigation

4 . 5 . 1 Data for the a i r fl ow rate 4 . 5 . 1 . 1 Range and mean va l ue 4 . 5 . 1 . 2 Reference regress ion l i ne

4 . 5 . 2 Data for the s ubgl otti c press u re 4 . 5 . 2 . 1 Range and mean val ue 4 . 5 . 2 . 2 Reference regress ion l i ne

4 . 5 . 3 Data for the effi ci ency 4 . 5 . 3 . 1 Range and mean val ue 4 . 5 . 3 . 2 Reference regression l i ne

4.6 Normal and deviant sounding phonations from the

same subject: intra-individual comparison

Chapter 5 Investigation conducted in patients

5.1 Introduction

5.2 Survey of patients classified in Groups

5.3 Results of first measuring series in all patients

5 . 3 . 1 D i scu s s i on of the aerodynami c data 5 . 3 . 2 Di stri buti on of normal and devi ant

regres s i o n l i nes

XI

79

82 82 82 88 89 89 90 9 1 9 1 9 3

94

9 9 9 9 99

103 104

106

X I I

5.4 Results of a l l measuring series in all patients

5 . 4 . 1 I nt roducti on 5 . 4 . 2 GROUP I , Pati ents sufferi ng from orga n i c

di s turbances o f the vocal fo l ds

108 108

108 5 . 4 . 2 . 1 I ntroduct i on , d i v i s i on i n subgroups 108 5 . 4 . 2 . 2 Di s cu s s i on on the experimental data 1 10

Hyperaemia 1 10 Oedema 1 1 1 Nodul-es 1 12 Pol-yps and/or cysts 1 15 Papil-l-omas 117 Chronic hyperpl-astic "Laryngitis

and/or "Leukopl-akia 1 18 Squamous carcinoma

5 . 4 . 2 . 3 Concl u s i ons 5 . 4 . 3 GROUP I I , Pati ents havi ng norma l vocal fo l ds

and , i n mos t cases , s l i gh t adduction

120 123

d i s turbances : " functi onal voi ce di s orders " 1 24 5 . 4 . 3 . 1 I nt roduction , speech therapi s t ' s

di agnos i s 124 5 . 4 . 3 . 2 Di scuss ion on the experimental data 127

Sul-cus glottidis

Psychogenic dysphonia

Spastic dysphonia

General- discussion

5 . 4 . 3 . 3 Concl usi ons 5 . 4 . 4 GROUP I I I , Pati ents having norma l vocal fol ds ,

but sufferi ng from severe i nnervation di s turbances

128 128 130 1 30 133

1 34 5 . 4 . 4 . 1 I nt roduction 1 34 5 . 4 . 4 . 2 Di scus s i on on the experimental data 1 36

Unil-ateral- laryngea l para lysis 136 Bilateral laryngeal para lysis 1 39 General discussion 144

5 . 4 . 4 . 3 Concl u s i ons 146

Chapter 6 Investigation conducted with trained singers

6. 1 Introduction

6.2 Flow, subglottic pressure, and efficiency of phonation

in trained singers

6.3 Qualitative aspects of the singing voice

6 . 3 . 1 Qual i ty of the s ung tones ; v i bra to and

147 147

149 1 55

the s i ngi ng formant 1 5 5 6 . 3 . 2 Acoust i c coupl i ng o f vocal tract a n d l arynx 156

6.4 Variants of the singing voice production 159 6.5 Conclusions 162

Chapter 7 Summary 163

Samenvatting 168

References 1 74

Appendix 19 5

XI I I

Chapter 1 Introduction

The human vo i ce may wel l be con­s i dered to be the ma i n mean of express i on of mank i nd . Human bei ngs not only pos sess the un ique g i ft of s poken l anguage , they al so can express emoti ons , thoughts and observati ons in a vari egated and personal way .

The voi ce provi des the acoust i ca l bas i s o f commun ication v i a s poken l anguage , by whi ch peopl e may ac­qu i re knowl edge and orga n i ze the i r though ts a n d pi cture of t h e worl d . Lang uage a l s o s erves a s the medi um by whi ch c i vi l i zat ion i s trans­ferred from generat ion to genera­t ion and di ffus ed geograph i cal l y .

Vocal sound , needed f o r s peech , is produced i n the l arynx . Th i s >as i c sound i s model l ed by the 1coust ica l properti es of the vocal �ract i nto the percei ved vocal ;ound . The di fferent speech sounds 1re formed by purposeful adj ust­nent of the speech organs .

Communi cation vi a spoken l a n­guage is hampered o r even rendered imposs i b l e when the produc tion of vocal sound causes probl ems .

A certa i n l evel of sound i nten­s i ty is necessary fo r s peech com­muni cat i on . Whether the sound i n­tens i ty i s suffi c i ent or not , de­pends pa rtly on the eff ic i ency of the l a rynx as a sound source .

It may be expected that the effi -

ci ency of vo i ce product ion i s de­creas ed i n the case of pa t i ents wi th vo ice prob l ems . Produci ng an adequate sound i ntens i ty then req u i res more than norma l effort .

From the l i terature concern i ng vo i ce product ion , i t appears that so far no sys temat ical i nvesti ga­t ion wi th respect to the effi ­ci ency of phonation has been ca rri ed out .

I n v i ew of the compl exi ty of the phys i o l ogy of phonation , i t seems adv i sab le to beg i n our con­s i de ration wi th a survey of the various phys i ol og ical factors of importance . For a descri ption of the ana tomy of the l a rynx we refer to the s tanda rd manua l s of anatomy .

The v i b rat ion of the vocal fo l ds i s i nduced by a compl i cated com­bi na t i on of aerodynami c , muscul ar , and e last ic forces i n the l a rynx .

Accord i ng to the myoe l a s t i c­aet·odynami c theory of phona tion ( van den Berg , 1958) the subgl ot­tic pressure is ra i sed after the vocal fol ds have been adducted . When the s ubgl otti c pressure i s h i qh enough to overcome the re­s i s tance of the adducted vocal fol ds , these wi l l d i verge and a i r wil l escape v i a the gl otti s . Owi ng

1

to the narrowi ng at the gl otti s the vel oc i ty of the a i r i ncreases , res u l t i ng i n a decrea s i ng pressure i n the gl otti s i tsel f , caused by the Bernou l l i effect . The decrease of the subgl o tti c pressure as a consequence of the escap i ng of a i r v i a the gl otti s , the i nwards suck­ing acti on by the Bernoul l i effect on the vocal fo l ds , and the el as­ti c i ty of the vocal fol ds , resu l t i n the i r return to the m i d l i ne pos i ti on and ( i n ches t reg i s ter) cl osure of the gl otti s . If the subgl otti c press ure is aga i n ra i sed suffi c i ently hi gh to di vert the vocal fo l ds , the v i b ration cyc l e s ta rts once more . The resul ti ng ti ny burs ts of a i r v i a the gl ottis cons ti tute a source of sound , the frequency of whi ch i s determi ned by the i r rhythm.

The vocal fo l ds are made to v i ­brate by a s tream o f a i r , but the pa ttern of v ibrat ion is pri ­mari ly determi ned by l a ryngeal cond i t i ons . The adj ustment of the l a rynx depends on the degree of contracti on of i nternal and ex­ternal l a ryngea l muscl es . The i n­nerva tion of thes e mus c l es , regu­l ated by the central nervous sys ­tem , guarantees control of tens i on and el asti c i ty of the muscl e s . I n adjust i ng the contraction o f these musc l es before and duri ng

2

phonation , an important ro l e i s pl ayed by the acti on o f a great number of mechanoreceptors . A sur­vey of the neuromuscul a r regu l a t ion of phonat i on has been publ i s hed by Wyke ( 1974a , b , c , d , lg76 ) .

By changi ng the adj ustment of the l arynx the resul t i ng vocal sound may be vari ed i n pi tch and i n tens i ty .

I ntens i ty and t imbre depend on the way i n whi ch the form and the area of the g lott i s change duri ng the v ibration cyc l e , i . e . the qua l ­i ty ( ti mbre ) of the vo i ce depends on the gl ottal wave form. I n add i ­tion the confi guration o f t h e vocal tract has an i nfl uence on the ul ­ti mate qual i ty of the sound . I n ches t regi s ter the gl otti s i s open during a part of the v i brat ion cycl e and rema i ns cl osed duri ng the other pa rt . The fracti on of the time duri ng whi ch the gl ott i s i s open duri ng the vi bra t i on cycl e has been ca l l ed "open quo t i ent" . Ai r can only escape duri ng the open pha s e . Therefore the fl ow i . e . the vol ume of a i r per uni t of t i me pa s s i ng v i a the gl otti s , seems to be an important criterion for the func tion of the l arynx .

The volume o f a i r al l owed to es­cape per vi bration cyc l e a l so de­pends on the adjustmen t of the l a ryngea l muscl es . Th i s adj ustment

determi nes the necessary hei ght of the s ubgl otti c pressure requ i red to open the gl otti s . The sens i t i ve mechanoreceptors i n the s ubgl otti c space react to t i s s ue tracti on , respondi ng to the s ubgl ottic press­ure and thus contri bute to the reg u l at ion of phona t i o n .

F o r a more extens i ve des cri ption of the myoel ast i c-aerodynami c the­ory of vo i ce producti on and other aspects of voca l phys i o l ogy and speech we refer to pub l i cati ons of van den Berg ( 1958 , 1968) , and manual s of e . g . Mi n i fi e , H i xon , and Wi l l i ams ( 19 73 ) , and Hardcas tl e ( 19 7 6 ) .

I n pati ents s ufferi ng from vocal di s turbances phonat i on may be af­fected i n va ri ous ways : by al ter­ati o ns of the s tructure of the vo­ca l fo l ds and the superf i c i a l l ayer of epi thel i um , by d i s turbances of the i n nervation of some of the l aryngeal muscl es , or by �1rong use of the l a ry nx .

The connecti on bet�1een pathol ogi ­cal changes of the vocal fol ds , the total ly or pa rtly modu l a ted fl ow of ai r res ul ti ng i n a pul ­sati ng a i r stream comi ng from the l ungs , and the ul tima tely resul ti ng voca l sound have been s tud i ed by I ssh i k i , Yanag i ha ra , and Morimoto ( 1966 ) , Yanagi hara ( 1967a , b ) ,

I s s h i k i , Okamura , Tanabe et al . ( 1969 ) . Thei r theoret i cal and ex­peri mental i nvest i gat ions proved the ex i stence of a cl ose rel ation between segmentation of the a i r fl ow and the ens u i ng gl ottal pul ses wi th respect to the u l timately produced sound .

I n s ome pati ents th i s not only appea rs in the open quoti ent, but al so in the presence of a non-mod­u l a ted part of the a i r fl ow v i a t h e gl otti s , the so-ca l l ed wi l d a i r . The amount of a i r was ted per ti me-uni t not only costs more en­ergy , but the a i r stream i s al so i nc l i ned to turbul ence , which may be percei ved as breat h i ness .

The a i r fl ow rate seems to be an i nd i cator for the functioni ng of the l a rynx and as such has been s ugges ted as a d iagnos t ic measure i n studying l aryngea l d i s turbances by I s s h i k i and von Leden ( 1964 ) . A l ow fl ow may mean that the open quotient is smal l , only l i tt le a i r be i ng al l owed to pass per v ibration cyc l e . A sma l l open quoti ent i nd i ­cates the presence of sharp g lottal pul ses , which means more upper par­ti a l s i n the source sound . However , i f a l ow fl ow can be achi eved only by an adjus tment of the l a l·ynx �1 i th a cond i tion of h i gh muscu l a r ten­s i o n , t h i s may l ead to an unfavour­ab l e and l ess eff i c i ent resul t .

Such an adjus tment of the l a rynx requ i res a h i gh subgl ott i c pressure i n order to i nduce l a ryngeal v i ­bra t i o n .

Th i s shows that al one s tudy i ng the cons umpti on of a i r i n phonation is not suffi c i ent , but that eval u­ation of subgl otti c pressure during phonati on must be i ncl uded .

Energy for phonation i s s uppl i ed by el astic energy s tored i n the thoracic wa l l after i n spi rat ion and by the expi ratory mus cles ( Mea d , Bouhuys , and P roctor, 1968 ) .

The aerodynami c energy provi ded can be ca l cu l a ted fa i rly accurately from the product of the va l ues of mean a i r fl ow rate and mean subgl otti c press ure .

The effi ci ency of vo i ce produc­tion i s determi ned by re l ati ng the produced sound power to the aerodynami c power prov ided , the so-ca l l ed subgl otti c power .

Van den Berg ( 1956 ) s tudied for the fi rs t t ime the effi ci ency of vo i ce production i n a subject wi thout l a ryngeal d i s turbances at va rious sound i ntens i t i es and pi tches .

Later experimenters have deter­mi ned voca l effi ci ency in ei ght norma l subjects and one pat i ent only .

4

Aim of this st�dy

The mai n object of th i s study i s to es tabl i s h the degree to wh ich the eff ic i ency of phonation in var­ious vocal pati ents had been changed by thei r di sorde r .

Moreover , w e i ntended t o s tudy whether the measuri ng of aerody­nami c parameters pos s i bl y cou l d be a cl i n i cal ly val uab l e d iagnos tic measure in cases of vocal di sturb­ances .

I n order to obta i n reference data , measurements had to be per­formed i n a group of normal sub­jects wi thout vocal d i s turbances .

The therapeutic resul ts i n pa­t i ents with vocal di sturbances , c la s s i fi ed i n va rious categori es , was to be objectiv i zed by es tab­l i s h i ng the effic iency before and after treatment .

I n Chapter 2 , we present the experimental methods and the pro­cedu re for measuring the sound i n­tens i ty , the a i r flow rate , and the s ubglottic pres sure and for ca l cu l a t i n g the effi ciency at va r­ious pi tches i n the voca l compass ( phonetogram) . In our research , the s ubgl otti c pressure has been meas u red wi th an i ndi rect method , wh ich has been veri fi ed by a di rect metho d .

I n Chapter 3 , the analys i s and eva l uati on of the obtai ned data a re di scussed. For every meas uri ng seri es regress i on l i nes have been ca l cul ated , i n d i cat ing the rel ation of sound i ntens i ty to a i r fl ow rate , subg lottic pres s u re , or effi c iency .

I n Chapter 4 , the res u l ts ob­tai ned i n 63 s ubjects come up for di scus s i on and reference val ues are es tabl i s hed . Repeated measure­ments on the same normal subject enab l e us to arrive at a j udgement of reproduci bi l i ty and i ntra- i n­d i vi dual di spers i on of experimental data .

In Chapter 5 , the res ul ts ob­tai ned in 64 patients a re d i s ­cussed .

The resu l ts of i nvesti gati ons of phonati ons in tra i ned s i ngers are d i scussed i n Chapter 6 . Aero­dynami c and qual i ta t i ve aspects and the effi ci ency of phonation are compared wi th thos e of non­tra i ned voi ces .

In Chapter 7 , a s umma ry i s g i ven .

5

Chapter 2 Experimental methods

2.1 Introduction

In order to assess the effi ci ency of phonat i on , the s ubg lottal ly suppl i ed power has to be b rought i nto re l a t i on wi th the produced vocal power .

W e estab l i shed the vocal power by measuri ng the i ntens i ty of the sound at a certai n di s tance from the sound source.

The subgl otta l ly s uppl i ed power is eq ual to the product of the a i r fl ow rate q and the s ubgl otti c press ure p .

I t woul d be important i n th i s respect to know the exact rel ati on­s h i p between the vari at ions of the a i r fl ow ra te and the va ri a­tions of the subg lottic pres s u re duri ng a s i ngl e cyc l e of v i b ra­tion . Unfortunately , we cannot estab l i sh s uch a rel ati ons h i p . Therefore w e h a d t o be content to use the product of the mean fl ow rate and the mea n subg lott ic pressure , wh i ch i ndeed are measur­abl e . Th i s approach i s permi tted , beca use of a rather l o�1 modul at ion depth of the subgl otti c pres s ure duri ng phonat ion . Therefore p � p ( van den Berg , Zantema , and Doornenbal , 19 5 7 ; Ki tzi ng and Uifqvi s t , 1 975 ) . I n Formul a 2- 1

6

t+ 1 /P X dV "' t

t+ 1 jj x Jdv

t

-p X q ( 2-1 )

A s u rvey of our measur i ng equ i p­ment i s g i ven w i th the a i d of Fi g­u re 2- 1 . Various parts a re ex­pl a i ned i n more deta i l l a ter on.

The s ubject i s s i tt i n g on a cha i r , the fl owhead and mouthpi ece a re s i tuated i n s uch a way that an un­res tra i ned pos ture of nec k and l a rynx can be ma i nta i ned .

The s ubject breathes and phonates v i a a fl owhea d , wi th a mouthpi ece whi ch i s kept beb1een the teeth , a nose c l amp preventi ng the passage of a i r v i a the nose .

The mouthpi ece i s chosen t o pre­vent the vari at i ons of i ntens i ty res ul ti ng from changes i n the s i ze of the mouth open i n g . Al l pho­nations were made whi l e keepi ng the vocal tract in the pos i t i on fo r the formation of the vowel (a] ( ahead ) .

The s ubject i s as ked not to cough i nto the fl owhead in order to pre­vent mucous or sal i va from gett ing onto the gauze of the fl owhead .

Because swal l owi ng of sal i va wi th a mouthpi ece between the teeth ap­peared to be di ffi cul t , there is the poss i b i l i ty of sal i va runn ing i nto the fl owhead . I n order to pre­vent th i s a perspex connecti ng

m i �

recorder

Figure 2- 1. Schematic depiction of the experimental set up for the simul­

taneous measurement of sound intensity I , air flow rate q, variation of

lung volume V, and oesophageal pressure pes

' together with apparatus for

registering pes

-V diagrams .

pi ece wi th receptacl e i s i nserted between mouthpi ece and fl owhead , see Fi gure 2-3 .

The fl owhead i s connected wi th a pneumotachograph and a recorder .

The subgl otti c pressure was as ­certai ned i ndi rectly by measuri ng the pressure in the oesophagus . Th i s i ndi rect method necess i tates the determi nation of the vol umes of i ns p i red and expi red a i r . The val ue of these vol umes may be ob­tai ned by anal ogue el ectro n i c i n­tegration of the a i r fl ow rat e . For conti nuous i n tegration of the

a i r fl ow rate a modi fication of the pneumotachograph was necessary , and a dd i ti onal apparatus for the regi st ration of Pes ( oesophagus) - V ( l ung ) d i ag rams was req u i red .

The pressure i n the oesophagus is rel ated to the pulmona ry vol ume ( Buytend i j k , 1949 ; Fry , Stead , Ebert e t a l , 1952 ) . An automat ic correcti on of the measured pres sure i n the oesophagus Nith res pect to the momenta ry pul monary vol ume was effectuated .

The sound i ntens i ty was measured

7

Figure 2-2A. The experimental set up .

wi th the a i d of a m icrophone at a di s ta nce o f 15 em from the outlet of the fl owhead .

The effi c i ency was es tab l i shed at various pi tches1) and i nten­s i ti es .

The ta rget pi tch and i ntens i ty the s ubjects had to produce i n pho-

sory apparatus . The Fi gures 2-2 and 2-3 provi de

a survey of the compl e te mea suri ng eq ui pment .

2.2 Pitch and intensity

of phonation

nation were i nd i ca ted by add i ti onal Duri ng the i nves t i ga t i on the apparatus . The produced sounds were s ubject was as ked to phonate at reg i s tered and analysed by acces- vari ous pi tches and i nten s i ti es .

The target pi tch was i n d i cated but 1 ) The terminology "pi tch" is used not a l ways produced . The ran ge of in this monograph as a synonym of pi tches and i ntens i ti es evi dently fundamental frequency . depended on the vocal potent ia l -

8

Figure 2-2B . The experimental set up : --

1 . Microphone (Bruel and Kj aer ) ; 2 . Microphone amplifier ( Bruel and

Kj ae r ) ; 3 . Sound intensity indicator for the subject; 4 . Lilly F lowhead

(Mercury Electronics ) ; 5. Pneumotachograph (Godart ) ; 6 . Pressure trans­

ducer (Hewlett-Packard ) ; 7. Carrier amplifier ( Hewlett-Packard ) ; B. Fre­

quency counter ( Schneider ) ; 9. Pitch Prompter (Groningen University Lab­

oratory for Medical Physics ) ; 10 . Loudspeaker; 1 1 . Precision rectifier

with logarithmic convertor for the registration of sound intensity on

the recorder , with bui l t-in adjustable attenuator for the sound intensity

indicator (Laboratory for Medical Physics ) ; 1 2 . Drift indicator for the

Pneumotachograph , and amplifier for the expiration flow correction (Lab­

oratory for Medical Physics ) ; 1 3 . Apparatus for automatic compliance

correction ( Laboratory for Medical Physics ) ; 1 4 . Tape recorder ( Sony ) ;

15 . Osci lloscope ( Hewlett-Packard) ; 1 6 . X-Y recorder (Hewlett-Packard) ;

17. Ubiquitous Spectrum Analyzer ( Federal Scientific Corporation ) ; 18. Mingograph recorder (E lema-Schonander ) •

9

Figure 2- 3 . Detail of measuring set: microphone, flowhead, connecting

piece with fluid receptacle.

i t i es of the subject or pat i ent .

2 . 2 . 1 Cho i ce of pi tches and i ntens i ti es of voca l sounds

2 . 2 . 1 . 1 P i tch Prompter

Th i s prompter cons i sts of an os-ci l l ator with octave di v i de rs for the frequency range rel evant for the phys i o l ogy of the voi ce . By i nstal l i ng fou r formant fi l ters , adj usted to the formants of the vowe 1 [a] , a sound caul d be ob­ta i ned wh ich �1as easy to i ntone by

In order to i nd i ca te which pi tch a subject . The sound is made aud-had to be produced the Groni ngen i b l e v i a a l oudspeake r . Duri ng phD-Uni vers i ty Laboratory for Medical nati o n , the l o udspeaker has to be Phy s i cs ( D i r . : Prof . Dr . Jw . van den di sconnected i n order to prevent Berg ) cons tructed a Pi tch Prompter i nterference wi th the s ung s ound . accordi ng to our spec i fi cati ons . The exami ner, however , i s able to

10

l 110 dB

100 -r..,.......•:r ·-· "·-·/ �-·-"'

-·-· I •

1-A • ,/-/ ...... .. .:

90

80

70

60 I / ,-.�. ·-·-· ·-·-50

40

55 82.5 110 165 220 330 440 660 880 Hz

Figure 2-4 . Phonetogram of an untrained male voice . The sound intensity

has been represented in decibels ( IEC-A ) measured at a dis tance of 30 em .

The arrow indicates the spot of the register transition in phonation at

maximum intensi ty .

hear the tone v i a an ea rphone throughout the experi ment .

A di g i tal frequency meter ( Schnei der E l ectron i que CF 350) i s connected pa ral l e l to the l oud­speaker, i n d i ca t i ng the fundamenta l frequency o f t h e prompt sound i n herz .

1) The musical notations are taken

from the American National Standard

Terminology.

The range of the P i tch Prompter reaches from C2 ( 65 Hz ) to C7 ( 2093 Hz )1 ) . The adj us tment for frequenc i es of the d i aton i c sca l e on C major i s made pos s i b l e by swi tches ; there i s a band-spread­fi ne- tun i ng adj us tment i n a l i mi ted freque ncy range pos s i b l e . Th i s pos s i b i l i ty o f varying the adj ust­ment and readi ng off the frequency i n herz from the frequency meter was mai n ly used i n case a tone had

1 1

not been s ung accordi ng to the exampl e . In such a case , the exam­i ner i s ab l e to adjust the pi tch prompter to the actua l ly produced pi tch ( 2 . 2 . 2 ) .

2 . 2 . 1 . 2 Phonetogram

A phonetogram i s a g raph i c rep­resentati on of the vocal potenti a l ­i ti es wi th respect t o pi tch and i ntens i ty ( Cal vet and Ma l h ia c , 1952 ; Cal vet , 1953 ; Luchs i nger, 1953 ; Vogel sanger , 1954 ; Waa r and Damste , 1968 ; Schutte , 1975 ) , s ee Fi gure 2-4 .

The pi tch i s reg i s tered o n the hori zontal axi s of the phonetogram. Th i s axi s i s di v i ded i n octaves . The frequency span compri ses the h i ghes t and the l owest frequency i n wh i ch the vocal fo l ds a re abl e to v i b ra te . D n the vert i cal axi s the sound i n­tens i ty i s reg i s tered .

For practi cal reasons the timbre of the vo i ce i s not menti oned i n the d i s cus s i on of the phonetogram . I t i s of cou rse fea s i b l e to arri ve at a sys tem of reg i s trat i o n , e . g . wi th a c i pher- code , to i nd i cate the qual i ty of the vo i ce i n a cer­ta i n a rea . I t i s very di ffi cul t though to reach agreement on a genera l ly acceptabl e sys tem .

I n order to make a phonetogram ,

12

the subject i s i ns tructed to s i ng a tone at a pi tch i dentica l wi th the pi tch from the prompte r , a t fi rs t a s l oud a s poss i bl e and then as soft as pos s i b l e . The s ubject must s i ng the same vowel each t i me . M i nor vari ati ons o f the vowel proved to have l i ttl e i nfl uence on resu l ts . The maki n g up of a phonetogram usua l l y s ta rts at C4 ( 262 Hz ) ; then the dynami c compass is measured systemat ica l l y ti l l the h i ghes t frequency l i m i t has been reached . After t h i s the l ower tones are meas ured unti l the l owest frequency l imi t .

The sound i nten s i ty i s measured at a d i s tance of 30 em from the mouth with a microphone ( Sennhei ser MD 408N ) and a sound i ntens i ty meter devel oped i n the Groningen Uni vers i ty Laboratory for Med i ca l Phys i cs . Readi ng off the resul t on th i s meter i s made eas i er by us i ng sel f-swi tchi ng measur ing ranges from 35 to 85 dB and from 7 5 to 125 dB . The compl ete set meets the condi t i ons requ i red for a frequency characteri s t i c accord­i ng to the IEC s tandard for curve A. The obtai ned meas uri ng poi nt s are connected by stra i gh t l i nes . A phonetogram can be made wi th i n 10 to 20 mi nutes .

Si ngi ng at a requ i red pi tch i s certai nly not eas i l y effectuated

110 dB

100

90

80

70

60

50

40

l ,.. /0'0, p �r�H. 0.o o / •,-o' ·o r•c,m j-j '""\'O j /_ vo1cE (- voicE ,o· o-o-o �_· 0·0 /-. l!

/ -f------/0 • I /-!' ... o-o I • o-o-o •-•-•-•-e�o/T

I l C1 E1 G1 A1 C2 E2 G2 A2 Ca Ea GaAa C• E• G•A• Cs Es GsAs Cs Es GsAs C1

55 82.5 110 165 220 330 440 660 880 Hz

Figure 2-5 . Phonetogram of the voice of a singer training as a counter­

tenor because of the great range of his false tto voice .

by a l l s ubjects . Many vocal pa­t i ents appea r not to be very mu­s ical and have l i ttl e control over thei r vo i ces . Moreove r , the memory for tones has usua l ly been poorly devel oped . In s uch cases the mu­s i ca l keennes s of heari ng of the exami ner is o f g reat impo rtance.

val ues of sound i ntens i ti es at the actua l ly produced pi tches .

I f a certa i n tone i s not reproduced properly by the person , but at a p i tc h too h i gh or too l ow , the exami ner shoul d be abl e to hear that . He may confi ne h i msel f in s uch a case to reg i s te r i ng the

The phonetogram represented i n F i gure 2-4 , taken from a s ubject w i thout voca l tra i ni ng , shows i n wh i ch pi tches and w i th what dynami c potenti a l i ti es th i s subject can phonate .

A decrease of dynami c potent i a l ­i t i es may occur i n a certa i n pi tch a rea , espec i a l l y i n non- tra i ned voi ces . Th i s may be seen i n Fi gure 2-4 at the regi on i nd i cated by an a rrow . Th i s d i p in the u pper part

13

of the phonetogram , as a l ready descri bed by Ca l vet and Ma l h i a c ( 1g52) , i s rel ated t o speci fi c reg i s ters : for chest voi ce and fal s etto vo i ce , see Fi gure 2-5 .

I n th i s s ubject , who was gi ven l ess ons as a countertenor because he was ab l e to s i ng wi th a fal setto voi ce at an unusua l l y l ow p i tch , chest vo i ce and fa l setto voi ce cou l d be di s t i ngui shed on the bas i s o f the timbre di fference. I n the octave bel ow C4 the s ubject appea red to be ab l e to phonate both in ches t voi ce and in fa l setto vo i ce , though wi th l i mi ted voca l i n tens i ty i n fa l setto vo i c e . For exampl e , i n fal s etto voi ce he was not ab l e to phonate l ouder than 75 dB at a pi tch of G3 .

The majori ty of the pati ents appea red to have vocal potenti a l ­i ti es wh i ch di d not extend to the fal setto voi c e . The use of the voi ce was mos tly l imi ted to one regi ster onl y , wh i ch after Hol l i en ( 1972 , 1974) may be i ndi cated a s "modal regi s ter" : " i t i ncl udes the range of fundamental frequencies that a re normal ly used in speaki ng and s i ng i ng " .

2 . 2 . 1 . 3 Speaki ng vo i ce pi tch l evel

Because vocal di s turbances i n

14

da i ly l i fe occur ma i nl y in speech rather than s i ng i ng , i t was con­s i dered of i mportance to determi ne a l so the a verage speaki ng vo i c e pi tch l eve l . Th i s w a s determi ned i n th ree s i tuati ons: --

a . duri ng spontaneous conver­sat ion ,

b . dur i ng counti ng from 1 to 20 at a fai rly rapi d pace ,

c . i n the rec i tation of a stri ng of words (days of the week ,

months of the year ) , as commonly practi ced i n phoniatr ic exami nat i on ( Bohme , 197 2 , 1974 ; Pascher, 1975 ) .

2 . 2 . 1 . 4 P re-sel ected pi tches

I t was imposs i b l e to take measurements of the effi c i ency at many pi tches i n v i ew of the re­qu i red total t ime . I n order to ob­ta i n comparab le resul ts we there­fore made use of pre-sel ected pi tches . Starti ng from an a verage speaki ng voi ce pi tch of 110 Hz for the ma l e voi ce and 220 Hz for the femal e vo i ce , frequency s teps of ha l f an octave were take n . In Tabl e 2-1 the series of pre-sel ected pi tches i s g i ven which in an ar­b i t ra ry s equence were i nvesti gated .

Some pati ents �1ere u nabl e to produce voi ce at these pi tches .

I f a di sti nct preference for a

Table 2- 1 . Pre-selected frequencies . The extreme frequencies within

brackets >lere inves tigated if possible .

E2 A2 E3 A3 E4 A4 ES AS

ma l e voi ces ( 82 . 5 ) , 1 10 , 165 220 , 330 , ( 440) Hz

fema l e voi ces ( 165 ) , 220 , 330 , 440 , 660 , ( 880) Hz

certai n frequency appeared to exi s t we meas ured the effi ci ency at that frequency . These were cases , general l y , of a person who appeared not to be a b l e to vary s uffi c i ently the pi tch or was un­abl e to s i ng the requi red tone . I n

of resonance ( van den Berg , 1954) . These probl ems occurred sometimes i n wel l - tra i ned subjects at about 330 Hz , but coul d be c i rcumvented by us i ng a s l i ghtly di fferent frequency .

such i ns tances we had to accept the 2 . 2 . 2 P i tch o f the produced vocal sounds preferred frequency . It coul d be

assumed that these persons phonated i n thei r modal reg i s te r .

The use of pre- sel ected p i tches cl ea rly had some drawbacks . The subject i n Fi gure 2-4 had an average speaki ng vo i ce p i tch at about C3 ( 123 H z ) . At A2 ( 1 10 H z ) only very 1 i mi ted dynami c poten­t i a l i ti es cou l d be observed . Th i s frequency al ready was cl ose to the l ower l i mi t of h i s frequency spa n , so that i nves ti ga tion at 1 2 3 Hz prov i ded a much better impres s i on of the dynami c potenti al i ti es of the vo i ce in da i ly use than at 1 10 Hz .

Wi th the pre-sel ected pi tches , di ffi cul t i es due to coupl i ng prob­l ems may be observed as a resul t

Du ri ng every measuri ng series the produced tones were recorded on tape i n order to enab l e pi tch eval uation afterwa rds .

For th i s purpose we used a tape recorder ( Sony TC 105) wi th Auto­mat i c Vol ume Control , g i vi ng i den­ti cal i ntens i ti es i n a l l pho­nati ons , wh i ch proved to be an advantage , when l i s teni ng to the tape. W i th the AVC d i s torti on was no ti ceab l e only i n very l oud pho­nati ons where the i nput pre­ampl i fi er was overl oaded .

The pos s i b i l i ty of veri fyi ng the actual sung pi tch retros pecti vely is of great importance . Tra i ned subjects had no di ffi cul ty i n

1 5

s i ng i ng the prompted tone . W i th non- tra i ned persons and pati ents the resul ts were sometimes very surpri s i ng , especi a l ly at fi rs t attempts . Someti mes subjects ap­pea red not to be abl e to s i ng a tone at a l l at the req u i red fre­quency .

Moreover , octave and even q u i nt mi s takes often occurred , i . e . the tone was an octave or a qu i nt d i f­ferent from the gi ven prompt tone . I n octave mi s ta kes , the s ung tone of cou rse often coi nci ded wi th an­other of the stri ng of pre-sel ected frequenci es.

I t a l s o appeared that the task of ma i ntai ni ng the tone for a cer­ta i n duration at a cons tant i nten­s i ty i tsel f al ready demanded much concentra t i on . S i nce frequency changes produced only s l i ght changes in dynami c output , we s tressed the demand for a constant sound i ntens i ty i n re l evant cases . Aften-1ards we then measured the actua l s ung pi tch .

2 . 2 . 2 . 1 Determ i na t i on of p i tch by audi tory eva l uation

The poss i b i l i ty of determi ning the p i tch by audi tory eval uat i on by match i ng the p i tch of the P i tch Prompter heard th rough ea rphones

16

wi th the actual sung p i tch during phonat ion appea red to be rel i abl e .

Establ i sh i ng the pi tch dur i ng phonat ion dema nds some mus i ca l s k i l l and experi ence i n compa ring p i tches , because phona t i on does not l ast very l ong. After phonation a compari son may be made between the remembered sung pi tch and the varyi ng prompter tone , i n the cou rse of wh i ch the memory i mage , however , i s rapi d ly effaced by the conti nual hear i ng of the "seek i ng " prompter tone. I n us i ng a tape recorder the actual sung tone may eventua l l y be repeated .

2 . 2.2 . 2 Instrumental deter­mi nati on of p i tch

It is important to be i nformed on l i ne about the actual sung p i tch . Therefore we s tu d i ed the poss i b i l i ti es of obta i ni ng d i rect regi s trati on wi th the a i d of a va i l able apparatus . Severa l devi ces were avai l ab l e : --

a. an el ectrogl ottograph accord i ng to Fabre ,

b . a Froekjaer-Jensen p i tchmeter , c . a Mel odyrecorder , and d . a Frequencycounter �Ji th

acces sory fi 1 ters . Al l appeared to be very useful ,

provi ded the actual sung p i tc h rema i ned wi th i n the sel ected

measurement range of the apparatus . However, adj us tment of the fre-q uency range of the i ns truments

2 . 2 . 3 Qual i ty o f produced voca l sound

proved to demand too much attention Nea rly a l l tape-recordi ngs were from the exami ner duri ng the tes t . checked aften-1ards by tra i ned Therefore we abandonned d i rect i n- s peech thera p i s ts , who judged the strumental regi s trat ion of pi tch . qual i ty of the phonati on . A pho-

In a l ater s tage of our study , nation was j udged as normal i f i t we had the opportuni ty to use an d i d not sound hoarse or breathy , Ubi q ui tous Spectrum Ana lyzer , Model or conta i n some other devi ati ng UA-6B ( Federa l Sci enti f i c Corpor- qual i ty . ati on ) , wh i ch permi tted determi -nat i on of the fundamenta 1 frequency 2.3 Measuring of sound intensity,

from the spectrum on an osci l l o­s cope screen . The analyser was adapted i n such a way that the voca l sound was analysed from 0- 500 Hz wi th a nomi nal frequency resol ­uti on of 1 Hz , or for p i tches from 0- 1000 Hz , wi th a nomi nal frequency resol uti on of 2 Hz.

The analyser is equ i pped wi th a hol d ci rcui t , wh i ch is acti vated duri ng phonat ion ; a fter the pho­nati on the " poi nter" on the os­c i l l oscope screen may be put above the fundamental frequency , in order to assess the frequency .

Taki ng i nto account tha t the tone that has been s ung never i s qu i te s teady , we rounded off on a mul ­t ip l e of 5 H z . I f the appa ratus was not avai l ab l e duri ng a l i ve measuri ng s eri es , frequencies were 1 ater determi ned �li th i t ·from the recorded tape .

total sound power

2 . 3 . 1 Sound i ntens i ty

The sound i ntens i ty was measured at a d i stance of 15 em from the outl et of the fl owhead . A condenser mi crophone ( BrUel and Kjaer 4145 , cathode fol l ower 26 1 5 ) connected to a measuri ng amp l i fier (BrUel and Kjaer 2606 ) was used .

The frequency characteri sti c was adj usted to the condi ti ons speci f ied for IEC s tandard curve B .

I n nearly a l l cases the weakest phona t i on appea red to ri se above a l evel of 60 dB (SPL ) . Th i s was wel l above the no i se of the back­ground , wh i ch vari ed from 40 to 45 dB .

For graphi c recordi ng of sound i ntens i ty i n dB on the Mi ngograph

17

recorder the Groni ngen Uni vers i ty Laboratory for Medi cal Phys i cs de­vel oped a prec i s i o n recti fier wi th a bui l t- i n l ogari thmi c converte r . The smoothi ng fi l ter of th i s con­verter has an i ntegration t ime of 15 ms .

Wi th the a i d of a "wi ndow-di s ­crimi nator" arrangement before the recti fi er we ens ured that an a daptab l e constant output s i gnal woul d be provi ded if the s i gnal fel l outs i de the l i near pa rt of the dynami c range of the rect i fi e r . The l ower l i mi t l evel o f the "window-di s crimi na tor" was usua l ly adjus ted at 60 dB , the l i near part of the dynami c ra nge was 55 dB .

The output of the conve rter i s a l so connec ted wi th a pa nelmeter v i a an adaptab l e attenuator . Thi s meter i s pl aced di rectly i n front of the person and acts as i nd i cator of sound i ntens i ty . W i th the a i d of the attenuator the sens i ti vi ty of the meter can be adj usted to assure that the req ui red i ntens i ty of sound wi l l be reached when the need l e of the me ter is i n the m i dd l e of the s ca l e .

The appa ra tus was cal i b rated i n deci bel w i th a p i s tonphone ( B rUel and Kjaer 4220 ) i n accordance w i th the prescri bed procedure . The de­v i ati ons were smal l er than� 0 . 2 dB . The frequency characteri s t i c

18

was checked wi th a Beat Frequency Osci l l ator ( BrUel and Kj aer 1022 ) and a Level Recorder ( B rUel a nd Kjaer 2305 ) and met the requi re­ments of the IEC s tandard for curve B .

Before e very measurement the adj us tment of the apparatus was veri f i ed by maki ng use of a bu i l t­i n reference s i gnal i n the meas uri ng ampl i fi e r . By varyi ng the i nput sect i on of the measuri ng amp l i f ier in s teps of 10 dB l i nea r control of the who l e set-up for sound i ntens i ty regi s tra t i on was pos s i b l e .

The i nfl uence o f the room acous ­tics ( eventual resonances ) , was exami ned by compari ng the frequency dependent transmi s s i on c haracter­i s t i c i n an anechoi c room to that in the exami nation room . An Art i fi ci a l Mouth ( B rUel a nd Kjaer 4219) was used as sound sourc e . The measuri ng m icrophone was s et at 15 em, 30 em respecti vely 100 em from the sound source . For the im­porta nt frequency range of 100 Hz to 4000 Hz these characteri st i cs were i dent i cal , apart from add i ­t i onal noi s e i n the exam i n i ng room . The di fferences due to the di s­tances �/ere taken i nto a c count (6 dB for 15 � 30 em and 10 dB for 30 -> 100 em).

From th i s fo l l ows that the i n-

ten s i ty measured at a di stance of 15 em i s representati ve . The amb i ent no i se s pectrum fl uctua tions in the exami n i ng room were l ess than � 1 . 5 dB and therefore cou l d

be negl ected .

2 . 3 . 2 Total sound power

In order to ca l cul a te the tota l sound power we s tarted from a known approach ( van den Berg , 1956 ) . We assumed that the sound i ntens i ty i s cons tant on the surface of a hem i s phere i n front of the fl ow­head ' s outl et . The centre of th i s sphere l i es i n the centre of the outl et of the fl owhea d . We assumed that the sound energy on the other hal f of the sphere cou l d be neg­l ected .

The total sound power then amounts to 2nr2 I , i n wh i ch r i s the rad i us o f the sphere ( i n our case 15 em ) and I the i ntens i ty of sound measured at thi s di stance i n front of the outl et . I i s meas ured i n d B SPL , i . e . the s tandard val ue in the equati on for the i ntens i ty amounts to 10-12H/m2 .

2.4 Measuring of air flow rate

(flow)

I n our experi ments the a i r fl ow

.>--"-''

Figure 2-6 .

Godart Pneumotachograph with Lilly

flowhead . Eventual drift is in­

dicated on the small meter bela>�

( 1 ) . With the potentiometer ( 2 ) ,

the proper expiration fl01< cor­

rection factor may be adj usted to

prevent the volume curve from

drifting .

rate was measured wi th a Pneumotachograph ( Godart model 1 72 12 ) , Fi gure 2-6 , wh i c h had been modi fi ed accord i ng to our spec i ­

f i cati ons .

19

2 . 4 . 1 Descri pti on of the pneumotachograph

A fl owhead ( fl ow-press ure trans ­ducer) acts o n t h e pri nci pl e that a res i s tance in the res pi ratory tract gi ves ri s e to a press ure d i fference p = q X R ( 2- 2 ) i n wh i ch p i s t h e d i fferenti a l pressure over t h e fl owhead , q the a i r fl ow rate and R the res i stance . The pressure i s l i near proporti onal to the a i r fl ow rate i f the re­s i s tance is cons ta n t . Th i s i s the case i f in a gas of cons tant com­pos i ti on and temperatu re the fl ow has a l aminar character . The con­struction of fl owheads a i ms at ach i evi ng th i s condi t ion for a cer­tai n range of a i r fl ow rates .

We eva l uated two di fferent types of fl owheads : the Fl e i sch fl owhead , cons i sti ng of a number of para l l e l

of the cyl i nders , r the i r rad i us and n the i r number.

We experi enced a number of d i f­fi cul ti es i n practi ca l use because n is not a s impl e quanti ty . For i deal gases , i . e . gases i n which the mol ecul es may be con s i dered as very sma l l e l a s t i c g l obul es , not excerc i s ing fi el d forces on each other , Maxwel l deri ved that n i s proportional to I T a nd i nde­pendent of press u re ; T i s the ab­sol ute temperature . In a m ixture of i deal gases the vi scos i ty of the mi xture equa l s the wei ghted s um of the vi scos i ties of the com­pos i ng gases . In practi ca l use th i s ca l cu l a t i on requi res correction ( Kesti n , 1963 ) . However , in v iew of an ana l ys i s of the i nfl uence of ma i n factors , the v1ei ghted sum can be used as a fi rst a pprox i ­mat i on for cal cu l ati ng the vi s­cos i ty of a gas mi xture .

connected cy l i ndri c tubes ( Fl e i sch , 2 . 4 . 1 . 1

1925 , 1956 ) and the L i l l y fl ow head

Choice of the fl owhead

w ith a fi ne-meshed gauze ( L i l l y , 1950 ) . For the Fl ei s ch fl owhead at l aminar fl ow the fol l owi ng formul a is appl i cab l e

81 R = n x mrr4 ( 2-3 )

I n thi s equation n i s the v i s­cos i ty of the gas , i s the l ength

20

In the s tandard model the Pneumotachograph i s del i vered wi th a Fl e i sch fl owhea d . Th i s fl owhead is composed of metal tubes and has to be heated in order to prevent condensation of aqueous vapour i n the expi red a i r . The regul at ing effect of the heati ng sys tem ap­peared to i nfl uence the pres s ure

d i fference and therefo re the a i r

fl ow rate deri ved from i t .

I n admi n i s teri ng d ry a i r a t a

constant fl ow rate and tempera­

ture the measured vari at ions i n

the a i r fl ow rate appeared to be

about 2 . 5� . The var i ati ons are

approximately i ndependent of the

mean fl ow rate .

The temperature of the a i r

l eav i ng the fl owhead was measured

by an el ectroni c thermometer and 0

appeared to vary between 34 . 5 C and 42 °C , i . e . the vari ati ons

0 amounted to about � 4 C . The effect on the fl ow measure­

ment has to be expl a i ned by the i nfl uence of the temperature on the v i s cos i ty and the vol ume var­i ati ons go i ng a l ong wi th tempera­ture var iat ions .

In the menti oned temperature range the tempera ture coeffi ci ent of n for a i r is about 0 . 2%/°C . The vi scos i ty then changes about + 4 x 0 . 2 = + 0 . 8% and the vol ume vari ati ons at cons tant pres sure amount to + 4 x 0 . 3 7% = + 1 . 5% . Taken together , th i s means va r­iati ons of � 2 . 3� . i . e . var i ati ons of the same s i ze as the mea sured ones . These va ri ati ons are per­mi s s i b l e if only the a i r fl ow rate is of importance , but wi th i nte­grati on of th i s quant i ty over a fa i rly l ong time thei r effect

proved to be cons i derab l e . I n order t o avo i d th i s d i sadvan­

tage we used a fl owhead accord i ng to L i l ly . Th i s fl owhead has a cover of synthet i c materi a l and a fi ne­mes hed metal gauze , both wi th a sma l l heat capaci ty . Therefore condensation of moi s tu re from ex­pi red a i r does not occu r , wh i ch makes heati ng of th i s fl owhead superfl uous . An add i t i onal advan­tage is that the subj ect may i n­s pi re a i r at room temperature .

2 . 4 . 1 . 2 L i neari ty of the pneumotachograph

The l i neari ty of the pneumo­tachograph system i nc l uding el ec­troni cs was tested by applyi ng known press u res , measured wi th an obl i que tube manometer , at the i nput of the apparatus . The pneumo­tachograph appeared to be l i near up to an output s i gnal of 9 Vol t , respecti vely - 9 Vol t . The sens i ­t i vi ty coul d be adj u s ted between about 40 Pa (4 mmH20 ) and about 80 Pa (8 mmH20 ) for an output vol tage of 5 Vol t .

l� e used a L i l ly fl m�head ( �1ercury El ectron i cs Ltd , Gl asgow ) , with a typi ca 1 pressut·e d i fference for room a i r of norma l tempera tu re of 24 Pa ( 2 . 4 mmH20 ) for 1 l / s . The fl owhead was used wi th the pneuma-

2 1

tachogra ph for an output vol tage of 5 Vol t at 2 1 /s .

For the purpose of cal i b ration we used a Goda rt Ca l i b rat ion set i n series wi th the Li l l y fl owhead . The cal i b ration set cons i sts of a number of tubes wi th a cal i ­brated openi ng . W i th the a i d of a pump an adj ustab l e a i r fl ow can be conducted through these tubes . The pres s u r2 di fferences are measured at the ca l i brated openi ng by an obl i que tube manometer be­l ongi ng to the ca l i brat ion set . For th i s cal i b ra t i on room a ir was used .

The res ul ts o f the meas u rements are represented i n Fi gure 2- 7 . W i thi n the random measuri ng error the compl ete set up appea red to be l i near i n both di recti ons up to an a i r fl ow rate of 2 1 / s .

The proporti ona l i ty factor of the fl owhead we used appeared to amount to 32 . 5 Pa . s / 1 ( 3 . 25 mmH20 . s/l ) .

2 . 4 . 1 . 3 Res ponse time of the pneumotachog raph

The res ponse time of the d i f­ferenti al pres s u re transducer has been s tated by the ma nufacturer to be smal l e r than 15 ms . From the regi s trati ons i t appea red that the use of the L i l l y fl owhead ,

22

connected to the pneumotachograph by fl exibl e tubes ( l ength 190 em , i nner di ameter 3 mm) , i nfl uenced the reaction speed of the system very l i tt l e o n l y .

The separate pul ses o f a i r caused by openi ng and cl osi ng the g lott i s duri ng phonation cou l d not b e ob­served . The mean a i r fl ow rate was regi stered , meeti ng our purpos e . Duri ng very 1 0�1 pi tches an i nd i ­cation o f the pu l sati ng character of the a i r fl ow cou ld be observed .

2 . 4 . 2 Properti es o f gases pas s i ng the fl owhead and thei r i nfl uence on fl ow measurement

In tes t i ng the pneumotachograph , room a i r was used . Duri ng pho­nati on , room a i r i s i ns p i re d , but the expi red gas has a di fferent compo s i t i on and tempera ture . Th i s i nfl uences the factors q and R i n the Equat ion for the di fferenti a l pressure ( 2-2 ) , as i s known from the l i tera ture on pulmonary func­tion and anaesthe s i o l o gy ( L i l ly , 1950 ; S i l verman and Whi ttenberger , 1950 ; Ba rtel s , BUcherl , Hertz et al . , 1959 ; Gree r , 1964 , 1966 ; Grenvi k and Hedstrand , 1966 ; Grenv i k , Heds trand , and Sjogren , 1966 ; Herzog , 197 0 ; Osborn , Beaumont , Ra i son et al . , 1968;

9 VOLT

7

5

3

-3 -2 -1

- 3

- 5

-7

-9

2 3 q (1/s)

Figure 2- 7 . Linearity of the Lilly flowhead . On the X-axis , the air flow

rate , adjusted with the Godart Calibration Set , is depicted in liter/s ;

on the Y-axis , the output voltage of the Godart Pneumotachograph is

given . The sensitivity of the Pneumotachograph has been adjusted in such

a way that an air flow rate of 500 ml/s provides an output voltage of

1 . 25 v .

Egan , 1969 ; Fl etcher , 1969 ; Osborn , E l l i ott , Segger et a l . , 1969 ; Bl umenfel d , Turney , and Cowl ey , 1973 ; Turney and B l umenfe l d , 197 3 ; Bl umenfel d , Wi l so n , and Turney , 1974 ) .

Data concerni ng i nspi red a nd ex­pi red a i r and thei r compos i t i on can be found i n the l i terature (O ti s , 196 5 ; D iem and Lentner ,

1968 ) , see Tabl e 2-2 . I t �1as as­s umed that the i nspi red air is 50 saturated wi th water vapour . The di fferences , wi th respect to the percentages of co2 and water vapou r , a re cons i derab l e .

2 . 4 . 2 . 1 Di fference i n vi scos i ty of i nsp i red and expi red a i r

23

Table 2- 2 . Gas composition of respiratory air in percentages , at a

pressure of 1 0 1 kPa { 760 mmHg ) . For inspired air , a relative humidity

of 50% at 22 °C was assumed. Expired air was considered to be 100\

saturated with water vapour and to have a temperature of 3 7 °C .

Insp i red a i r Expi red a i r

FN 2

7 7 . 99 74 . 87

From handbooks { H i rschfel der, Curti ss , and B i rd , 1954 ; Lange , 1967 ; Wea s t , 1968) the vi scos i ty of va ri ous gases may be deri ved , Tab l e 2- 3 .

Assumi ng that the vi s cos i ty of mi xtures of gases i n a fi rst ap­prox i mation equa l s the wei gthed sum of the vi s cos i t i es of the com­pos i ng gases , the v i s cos i ty of the i ns p i red a i r at 22 °C ( n22 ) , re­s pect i vely of the expi red a i r at

0 37 C ( n3 7 ) may be estimated as fol l ows n22 = 1 8 . 17 �Pa . s n37 = 18 . 38 �Pa . s

Des pi te the rel ati vely great d i f­ferences between i nspi red and ex­pi red a i r the di fference i n v i s ­cos i ty only amounts t o 1 . 1 3� . The addi tion to the mi xture of carbon­di oxyde gas and water vapour wi th a l ow v i s cos i ty and the withdrawa l of oxygen wi th a comparat i vely h i gh coeffi c i ent , a l mos t tota l ly com-

24

20 . 68 1 5 . 2 3

Fco 2

0 . 03 3 . 65

FH 0 2

1 . 3 6 . 25

pensates for the i nc rease i n the vi scos i ty caused by the r ise i n tempe rature .

From thi s c a l c u l a t i o n fol l ows that the res i s tance R i n Equat ion ( 2- 3 ) i s 1 . 13% l a rger for expi red a i r than for i nspi red a i r .

2 . 4 . 2 . 2 Di fference o f vol ume of i nspi red and expi red a i r

The vol ume o f the i nsp i red a i r i s di fferent from the vol ume of the expi red a i r because of di f­ferences i n temperatu re and com­pos i ti on . The total pres sure i s supposed to b e 101 kPa ( 760 mmHg ) . The changes of vol ume i n conse­q uence of a l tered compos i ti on and temperature may be ca l cu l ated by assumi ng that the amount of n i trogen a l ways rema i ns the same . N i trogen i ndeed i s wa rmed up i n i nspi ra ti on but the total amount of ni trogen in the exp i red m ix ture

of gases i s the same as i n the i nsp i red a i r . The a l tera t i on due to the change i n the compos i tion may be deri ved from the s i ze of the fracti ons (Tab l e 2-2 ) . The a l terations due to the change of temperature may be deri ved from the val ues of the absol ute tem­perature ( gas- l aws ) . I f a vol ume v1 contai ni ng 77 . 99% N2 and a tem­perature of 22 °C ( 29 5 K) i s i n­spi red and a vol ume v2 conta i n ing 74 . 87t N2 and a temperature of 37 °c ( 3 10 K ) is expi re d , then

V V 77 .99 310 2 = 1 x 74:""S/ x 295"

v1 x 1 . 0952 ( 2-4 )

I n breathi ng v i a the fl owhea d , i nteg ration of the fl ow s i gna l duri ng a steady state wi l l y ie l d a l a rger vol ume duri ng expi ration than duri ng i nsp i rat i o n . In th i s i ns tance the effect o f the v i s ­cos i ty acts i n conjunction wi th the effect of the vol ume accordi ng to the above menti oned cal cul ation , caus i ng a total i ncrease of about 11 � . Howeve r , due to the presence of a compa rati ve l y extens i ve dead space , not a l l of the expi red a i r may be cons i dered to be heated i ns p i red ai r .

The phys i ol ogi cal dead space is about 150 ml , moreover there i s the add i tional vol ume of the

Table 2-3 .

Viscosities of the air-constituent

gases , in micropascalseconds .

22 °C 37 °c

N2 1 7 . 7 18 . 5 02 20 . 3 2 1 . 3 C02 1 5 . 4 16 . 1 H20 9 . 9 10 . 5

fl owhead and the perspex connection of fl owhead and mouthpi ece . The total dead space therefore amounts to about 275 ml . The i nfl uence of a dead space of s uch an exten­s i on i s not negl i gi b l e , because per respi ration cyc l e a mi nimum of 350 ml i s necess a ry i n order to provi de the phys i o l og ica l l y req u i red refres h i ng of t h e a i r i n the l ungs . Al together , th i s practi cal l y wi l l cause the d i f­ference to be l es s than 1 1 % , more­ove r , the di fference wi l l be sti l l l ess because the expi red a i r i s a l ready somewhat coo l ed off when arri v i ng at the gauze .

2 . 4 . 3 Adj ustment o f the pneumotachograph

Because it was i ntended to measure the a i r fl ow rate in pho­nat ion , i . e . the f l ow rate of the expi red a i r , the i nstrument was

25

cal i b rated by means of a gas mi x­ture wi th properti es near ly i den­ti cal to those of expi red a i r , namely room a i r heated t o a tem­perature of 37 °C and saturated wi th water vapour to 100% . The computed v i s cos i ty of th i s humi d ca l i bration mi xture i s 1\ h i gher than that of expi red a i r , due to the l ack of co2 and the somewhat di fferent proporti ons of N2 and 02 . For the adj ustment of the pneumotachograph previ ous to each measuri ng series and for check i ng ca l i brat ion constancy after the seri es dry cal i b rat ion ai r from a cyl i nder �1as use d .

The a i r fl 0�1 ra te was regu 1 a ted wi th a prec i s ion need l e va l ve and measured wi th a Brook Sho-Rate Fl owmeter ' 250 ' model 2- 1357-8605 for the range from 80- 1200 m l / s (meteri ng tube R6- 25-A wi th Tantal um Fl oat ) . The v i s cos i ty of

th i s dry cal i b rati on ai r at 22 °C l i es nea rly in the mi dd le between the v i scos i ty of the i nsp i red a i r a t 2 2 °C and tha t o f the expi red a i r at 37 °C and , therefore , i s 1 . 5 sma l l er than the ca l cu l ated v i s cos i ty of the menti oned humi d cal i brat ion mi xture .

The correct adjustment and the check after the measurements a l ways took pl ace wi th the same fl ow rate of dry cy l i nder ai r . Th i s fl ow ra te

26

caused a pressure di fference equa l to that at the fl ow rate of 500 ml/s of the hum i d cal i bra tion mi xture.

2.5 Measuring of variations in

pulmonary volume

By time i ntegration of the d i r fl ow rate the changes o f the l ung vol ume can be determi ne d . Th i s i s important because there i s a cer­ta i n rel at ionsh i p between l un g vol ume and i ntra-oesophageal pressure .

For the i ntegration we made use of a modi fi cation of the el ectroni c i ntegrator , whi c h i s part o f the Godart Pneumotachograph , see F i gure 2-8 .

The expi ration fl ow s i gna l , a fter having been sepa rated from the i n­spi ra t ion fl ow s i gna l , was con­ducted further via an externa l l y adj ustabl e ampl i fi e r ; the i nsp i ­rat i on fl o�1 s i gnal was trans ferred una l tered . The amp l i tude of the transferred expi ration fl ow s i gnal coul d be adjusted between 90. and 100� of the detected va l ue . Th i s appeared to b e o f great va l ue i n the conti nual regi strat ion o f the vol ume curve , as dri ft coul d be corrected for . ( Th i s el ectron i c opti on was not ava i l ab l e i n the standard model of the pneuma-

q

inspiration

flow direction detector

integrator v

flow signal

expiration

adjustable amplifier 90 · 100°o

volume signal

Figure 2-8. Diagram of the set up for the expiration flow correction

method used in this investigation . The expiration flow signal can be

attenuated continuously to maximally 10 .

tachograph , but was added by the manufacturer to the apparatus , fol l ovl i ng our sreci fi cations . )

After pas s i ng the expi ra tion fl ow correction ampl i fi er the s i gnal was aga i n combi ned wi th the i ns p i ­rat i on flow s i gna l a n d fed to the vol ume i ntegrator .

The tota l va l ue for the vol ume i ntegrat ion i s l i mi ted so that i f a certa i n output vol tage i s reached ( pos i ti ve or negat ive ) automati c resetting o f the i ntegrator to 0 V (_:!: �50 mV ) wi 1 1 fo 1 1 01-1 .

The total range of the i ntegrato r compri sed 4 . 4 l i ter . Therefore the vol ume of the l u ngs dur i ng qu iet b reath i ng cou l d be reg i s tered wi th­out resetti n g , as wel l as the i n­spi rati on before phonation and the expi ration duri ng phonati o n .

2 .5 . 1 Cal i bration of f low and vol ume measu rement

In 2 . 4 . 3 has a l ready been men­ti oned that i n cal i bration of the pneumotachograph we s tarted wi th a i r of 37 °c , 100� satura ted wi th wa ter vapo u r . For practi cal pur­poses the fl ow cal i bration was performed s imul taneously wi th the ca l i bration of the vol ume i nte­grato r , by l etti ng an exactly known vol ume of a i r (2 l i ters ) of 37 ° c , 100w saturated wi th water vapour escape by means of a d i s ­pl acement method v ia the fl owhea d . A t a setti ng o f 100 for the ex­pi rati on s i gnal the sens i ti v i ty of the common fl ow ampl i fier was adjusted i n such a way that the vol ume i ndi cator reg i s tered 2 l i ters . At th i s adj us tment ai r from

?.7

a h i gh press u re cyl i nder was con­ducted th rough the fl owhead v i a t h e B rooks fl owmeter . The a i r fl ow rate was var ied i n order to obta i n i n 4 seconds a vo l ume i nd ication of 2 l i ters . The readi ng of the B rooks fl owmeter then corresponds wi th an a i r fl ow rate of 500 ml /s of a i r at 37 °C and a 100% satu­rati on wi th aqueous vapour . Th i s readi ng was used for l ater ca l i b ra t i on .

2 . 5 . 2 Regi s tra t i on o f vol ume c urve

The regi s trat i on of a vol ume curve may show devi a t i ons whi c h may l ead t o erroneous i nterpre­tati ons of the rel a t i on between l ung vol ume and oesophageal press u re . The mos t i mportant s ou rce of error i n th i s res pect l i es i n the use o f the fl owhea d , a s di s ­cussed i n 2 . 4 . 1 ; moreover , an i n­accurate zero adj u s tment o f the fl ow ampl i fi er may l ead to fau l ty reg i s trat i ons .

2 . 5 . 2 . 1 Course o f vol ume cu rve due to dri ft i n fl ow ampl i fi e r and/or i ntegrator

W i th zero fl ow , e . g . i n case of a d i s connected fl owhead , the

28

ampl i fi e r output and therefore the i nput of the i ntegrator ought to show a mean vol tage of 0 V. In s uch a case the output s i gnal of the i ntegrator should be consta n t .

A s a resu l t of fl uctuat i ons of temperature etc . , i t may occu r that a t zero fl ow the i nput vol tage of the i ntegrator i s not zero , i ntroduc i ng a dri ft i n the i nte­grato r . Because mi nimal dri ft i s of i mportance i n v i ew o f the ac­curacy wi th wh i ch the subglott i c press ure can b e meas u red , a s tanda rd has been establ i shed for the adjustment of the fl ow ampl i fier .

Measurements o f dri ft o f the pneumotachograph proved that a d­justment o f the fl ow ampl i fi e r at zero fl ow cou l d be performed i n s uch a �Jay tha t the output d i d not show a greater dev i a t i on from zero than � 1 mV , correspondi ng wi th � 0 . 2 m l/s and an i ntegrator d r i ft sma l l er than 60 ml during a per i od of 10 mi nutes .

For pract i ca l purposes the G roni ngen Un i ve rs i ty Laboratory for Medi ca l Phys i cs des i gned a dri ft i ndi cator to fac i l i tate the a dj ustment to l im it the dri ft to l es s than 60 ml duri ng a period o f 10 mi nutes . The dri ft of the ampl i fi er wi l l cause no probl em wi th i n the time needed for one

A B TIME (s)

/VV\/VVI.fV'Ifi/1/WvVVI/WvWV'

Figure 2-9 . Volume curves from a quietly breathing subject, with repre­

sentation of expiration flow , pressure variations in the oesophagus , and

lung volume curves . Because in normal phonation the inspiration flow is

of no importance , only the expiration air flow rates have been regis­

tered . In (A) the volume curve shows a drift in the direction of the

expiration ; in ( B ) the drift has been e liminated by a proper adjustment

of the expiration flow correctio n .

measuri ng . Duri ng the measur i ng series the

presence of d r i ft i n the fl ow am­pl i fi er and/or i ntegrator i s checked regul a rl y and corrected by adj us tment i f neces sary .

a fter i ntegrat ion o f the flow s i g­nal duri ng q u i et brea thi ng , a l a rger vo l ume was found for expi red a i r than for i nspi red a i r , see Fi gu re 2-9 .

Fi gure 2-9A shows a regi strati on of the changes in oesophageal pressure duri ng a period of q u i e t b reathi ng .

2 . 5 . 2 . 2 Course of vol ume curve due to di fferences i n phys i ca l p roperties Expi ration a i r f low rate and and vol umes of i ns pi red vol ume curve have been reg i s tered a nd expi red a i r s i mu l taneous l y . After some time

the course of the vol ume curve As a res u l t of the di fferences appea red to be di spl aced i n the

men ti oned in 2 . 4 , i n th� s ta ndard di recti on of the exp i ration . After model of the pneumotachograph , some 9 breaths of 700- 750 ml the

29

total vol ume of the l ungs s eems to be dimi n i shed by 500 ml , i . e . about 7 . 5 • . Thi s res ul t corre­sponded fa i rly �1el l wi th the ex­pected va l ue ( 2 . 4 . 2 . 2 ) .

By reduci ng the exp i rat ion fl ow si gnal by about 7 . 5� dri ft cou l d b e el imi nated from the vol ume curve , see F i gure 2-98 . ( Mead and Whi ttenberger , 1953 , arri ved a t s imi l a r correction data o n the bas i s of experimental s tudi es . )

The di ffe rence of the vol umes duri ng i nsp i ration and exp i rat ion depends on the temperature and rel at ive humi d i ty of the i ns p i red a i r at the moment of measuri ng . Previ ous to every measurement series the neces sary co rrection factor was experimental ly asses sed . Therefore �1e checked by i ns pection of ei ther the vol ume curve on the regi s tration paper during qu i et brea th i ng or the sp i ral dri ft i ng of the Pes-V l oops , see Fi gure 2-18 , to ma ke sure tha t dri ft no l onger occurred . If the correct i on had been adj us ted properly the l oops of s ucces s i ve respi rati ons were superimposed .

I n cons i deri ng th i s problem , we shou l d rema rk tha t i t i s sometimes attempted to correct the dri ft of the vol ume cu rve by a b i as of the fl o�1 ampl i fi er . If th i s i s done , then when the fl owhead i s di scon-

30

nected , there wi l l be a dri ft equal to that for wh ich the respi ration had been corrected , but in the oppos i te d i recti on . We cou l d not accept th i s method because when the breath is he l d there wou l d be a drift . Therefore we opted for the di scussed mod i f i cat ion o f the s tanda rd pneumotachograph .

2.6 Measuring of oesophageal

pressure

To meas ure the oesophageal pressure we used an oesophagus bal l oon s i tuated in the l ower 2/3 part of the oesopha gus .

The oesophagus ba l l oon w ith ca theter was i nserted through the nose a fter the mucosa had been anaes theti sed with oxybuproca i ne HCl ( Noves i neR ) .

The catheter wa s ma rked at a d i stance of 38 em from the ti p and i nserted unti l the ma rk reached the nos tri 1 and then �1as fi xed by adhes i ve pl aster .

The catheter was connected wi th a pres sure- transducer ( Hewl ett­Packa rd , 267 BC) wi th an ampl i fi e r ( Hewl ett-Packard , 88058 ) . The o utput s i gnal of the mea s ur ing ampl i fi er �1as transferred to the recorder .

0.5 ( ) { > I I

I

I I

I

I I

Figure 2- 1 0 . Oesophagus balloon catheter ( sizes in mm) .

2 . 6 . 1 Oesopha gus ba l l oon catheter

The oesophagus ba l l oon catheter ( Lode I ns truments B . V . , Groni ngen ) i s made of l a tex rubber , l ong 10 em , di ameter 1 em , wa l l t h i ck­ness smal l er than 0 . 15 mm . The bal l oon is fas tened to the end of a pol yethy l ene catheter wi th an i nternal di ameter of 1 . 8 mm , a l ength of 9 5 em and a wa l l th i ckness of 0 . 5 mm. I n the l ower pa rt of the wa l l of the catheter a number of hol es have been made , wh i ch are encl osed by the bal l oo n , see F igure 2- 1 0 .

The oesophagus bal l oon catheter is connected to a sys tem wi th three cocks that al so can be used a s ma ni fo l d connect i ng p iece . �li th the a i d of th i s system , the oesophagus ba l l oon catheter i s connected to : --

a ) the pres sure transducer , b ) an U-shaped water manomete r ,

and

c) an a i r- fi l l ed syri nge . For a correct transfer of the

pressure on the ba l l oon via the catheter to the pressure transducer a certa i n vo l ume of a i r has to be brought i nto the system .

An i ns uffi c i ent fi l l i ng , caus i ng the ba l l oon to be sucked i nto the hol es as wel l as a superfl uous fi l l i ng , whi ch causes the ba l l oon to be bl own up, may i nduce fau l ty reg i s tra tion of the oesophageal pressure (M i l i c-Emi l i , Mead , Turner et a l . , 1964 ; Tostmann , Siegert , and Kl i nghol z , 1979 ) .

Experimenta l resu l ts proved that rel i abl e data coul d be obta i ned wi th a fi l l i ng of a i r of 3 . 5 ml . The function i s control l ed by ob­servi ng the curves on the reg i s ­tration paper .

The nom i na l vol ume di spl acement coeffi c i ent of the transducer amounted to about 2 . 3 mm3;MPa ( 0 .03 mm3; 100 mmHg ) .

The changes of the bal l oon vol ume caused by the correspondi ng changes

31

of pressure duri ng phonation a re negl i gi b l e .

vari ati ons i n thi s shock tube were measured wi th a rap i d response pressure transducer and the bal l oon

2 . 6 . 2 L i neari ty o f the pressure catheter manometer system. Both meas u ri ng sys tem

The press ure transducer i s l i near for a range from - 13 kPa to +53 kPa ( - 100 mmHg to +400 mmHg ) .

The l i neari ty of the tota l sys tem was tes ted for the range from -5 kPa to +10kPa ( - 50 cmH2D to +100 cmH2D ) by p l a ci ng the bal l oon in a perspex cyl i nder i n wh i ch the pressure outsi de the ba l l oon coul d be varied . The res ul t i s repre­sente d i n F i gure 2- 1 1 . I t appea rs that the pressure i ns i de the bal l oon fol l ows the outs i de press ure wel l i n the perti nent range .

2 . 6 . 3 Response t ime o f the

outputs were s imul taneously reg i s ­tered o n the M i ngograph recorder with h i gh paper speed .

From these regi s t rati ons , the frequency res ponse was computed by the method descri bed by McDona l d ( 1960 ) , V i erhout ( 1963) , Yanof , Rosen , McDona l d e t al . ( 1963 ) , Yanof ( 1965 ) , Bottacc i n i , Burton , and L i m ( 1967 ) , and Wessel i ng and van Vol l enhoven ( 1969 ) .

A l i near dynamic response u p to 30 Hz was found . For reg i s tration of q u i et brea th i n g , 12 to 18 res ­pi rati ons p e r mi nute (0 . 2-0 . 3 H z ) , a l i nea r dynamica l behav iour up to 4 Hz i s consi dered to be s uf­f i c i ent ( McCal l , Hyatt , Nobl e et al . , 1957 ) . Therefore the mea su ri ng

pressure meas uri ng sys tem system works fast enough for regi s ­teri ng the mean pressure i n the

The al ready menti oned pers pex oesophagus duri ng phonation and cyl i nder was a l so used to measure the changes of pres sure s hortly the response t i me of the pressure a fter the onset or cessat ion o f mea s u ri ng sys tem . phonat ion .

For th i s purpos e , the bottom of the cyl i nder was rep l aced by a t i g h t rubber membrane . At a ra i sed pres sure i n the cyl i nder a sudden

2 . 6 .4 Ca l i bration of the pressure measuri ng sys tem

rel ease - necessary for the step The pressure measuri ng sys tem response - was i nduced by ruptu ri ng was cal i brated before eve ry the rubber membrane . The pres s ure measuri ng seri es by connecting i t

32

10

8

6

4

2

- 4 - 2 2 4 6 8 10

- 2 Pe ( k P a )

/ - 4

Figure 2- 1 1 . Calibration of the oesophagus balloon catheter manome ter

system with the aid of a pressure tank : pressure outside balloon , pe

'

pressure inside balloon , pi

.

to the water manometer .

2.7 Determination of subglottic

pressure

The subgl o tti c press u re can be meas ured by d i rect or i ndi rect methods . In a di rect method the pres sure is measured di rectly i n

the trachea . I n the pas t , several routes have been taken for thi s purpose : --

a . V ia a tracheostoma . Si nce the fi rs t measurements by

Cagn iard-Latour ( 1837 ) unti l about 1960 (S trenger , 1g58) , subg l ott i c pressure val ues were obtai ned i n thi s way ( Roude t , 1900a , b ;

3 3

Gutzmann and Loewy , 1920) . b . V i a the l a rynx. Van den Berg

( 1956 ) used a catheter con­ducted through the nose and the gl otti s and brought i nto the sub­gl ott i c space , to veri fy the re­su l ts obtai ned by an i ndi rect method descri bed by h im . Perk i ns and Koi ke ( 1969 ) and Ki tz i ng and Ltifq v i s t ( 19 7 5 ) used in the same way a catheter-t ip manometer for h i gh- frequency regi s trati on of the s ubgl otti c pressure .

c . V i a a hol l ow needl e per-cutaneo us l y i nserted i nto the

s ubgl otti c s pace . A cons i derab l e number of i nves ti gati ons , ma i nly ameri can , y i el ded s ubgl otti c pressure val ues ( I s s h i ki , 1959 , 196 1 , 1964 ; Strenger , 1959 ; Ladefoged , 1960 ; Kunze , 196 2 , 1964 ; McGl one , 196 3 ; I ssh i k i and von Leden , 1964 ; Yanag ihara and von Leden , 1966 ; Rub i n , LeCove r , and Vennard , 196 7 ; L i eberma n , 1968 ; Perki ns and Yanagihara , 1968 ; L oebel l , 1969 ; McGlone and Sh i pp , 1971 ; Murry , 197 1 ; �1u rry and Brown , 197 1 ; Sh i pp and McG lone , 197 1 ) .

For ob vi ous reasons the numbers of exami ned persons �1ere sma 1 1 . The di rect methods are not s u i ted for routi ne cl i ni ca l practi c e .

V a n den Berg ( 1956 ) i ntroduced an i ndi rect method for measuri ng the subgl otti c pressure . I n thi s

34

method , the subgl otti c pressure i s deri ved from changes i n oesophageal pressure . Du r ing res­pi rati on and phona tion the press ure i n the oesophagus i s measured . The oesophageal pressure is i nc reased duri ng phonati on , and the sub­gl otti c pressure duri ng phonat ion can be de ri ved from th i s i nc rease , but not wi thout payi ng attent ion to other factors . The reason i s that the pressure i n the oesophagus depends on the l ung mechani cs , cond i ti oned by certai n mechani ca l properties of t h e l ungs , as w e have al ready seen from variati ons i n oesophageal pres sure duri ng res­pi rati o n , see Fi gure 2-9 .

The method descri bed by van den Berg has been used for phoneti c research by Ladefoged , Drape r , and Whi tteri dge ( 1958 ) , Draper, Ladefoged , and Whi tteri dge ( 1959 ) , Strenger ( 1959 ) , Draper and Ladefo ged ( 1960 ) , Ladefoged ( 1960 , 1962 , 1963 ) , and Ladefoged and McKi nney ( 1963 ) .

Kunze ( 1962 , 1964 ) cri t i c i zed th i s i ndi rect method and cons i dered it not usabl e for measuri ng the s ubglotti c pressure .

He a rri ved a t th i s conc l us i on on the bas i s of h i s compa rati ve i nvest i gati ons wi th a di rect method ( punct ion of the tracheal space ) . We assume h i s s ubjects d i d not

perform the tes ts properly . The i ndi rect method i n i ts

ori g i nal vers i on requ i res an ab­

rupt phonation s top , the breath is hel d on wi th open gl otti s . Th i s manoeuvre demands some trai n i ng . Kunze measured i n fact the sub­gl otti c press ure together wi th a pressure dependent on the l ung vol ume .

I nduced by the concl usi ons d rawn by Kunze and the i r own erroneous l y i nte rpreted curves , Rubi n , LeCover , and Vennard ( 1967 ) a l so rejected the oesophageal bal l oon method .

Ladefoged ( 1964 ) , Bouhuys , Proctor , and Mead ( 1966 ) , Bouhuys , Mead , Proctor et a l . ( 1968) , L i eberman ( 1968) , and Schwabe and Si egert ( 1973 ) , di d not agree wi th Kunze ' s concl us i ons and poi nted out that the oesophageal bal l oon method is rel i ab l e i ndeed , pro­vi ded that the l ung vol ume is taken i nto account .

Th i s i ndi rect method was a l s o used by Cavagna and Ma rgari a ( 1965 , 1968 ) , and Cavagna and Campores i ( 1974 ) .

Si ege rt et al . ( S i egert , 1969 , 197 1 ; Kl i nghol z and S i egert , 1972 ; Si egert and Kl i nghol z , 197 3 ; Hafner and Si egert , 1975 ) used the i n­d i rect method at the onset of the voi c e . Therefore thei r res ul ts

cannot be compared wi th our data . N i s h i da and Suwoya ( 1964 ) de­

scri bed a so-cal l ed i nterrupti on method for i nd i rect measuri ng the subglottic pres sure . I n th i s method , the a i r stream v i a a breath i ng mas k i s temporari l y i n­terrupted and the i ncrease i n pressure wi th i n the mas k i s measured .

Ki ttel and Moser ( 1976 ) used a body p lethysmograph for determi ni ng the subgl otti c pressure in stut­terers . They re l ated the l ung vol ume ( obtai ned by i ntegration of the el ectri c s i gnal from a pneumotachograph ) and the i ntra­thoraci c press u re . The i ntra­thoraci c pressure i s rel a ted to the subgl otti c pressure duri ng phonation . The use of a body pl ethysmograph demands s k i l l ed personnel and much experi ence i n i nterpreti ng the obtai ned curves .

I n the fol l owi ng secti ons we wi l l further di s cuss the cal cul ations i n deta i l .

2 . 7 . 1 Correcti on for mechan i ca l propert ies o f the l ungs

The ro l e of the mechan ica l properti es of the l ungs i n ca l cu­l a ti ng the s ubgl otti c pressure may be expl a i ned wi th the a i d of the Pes-V d ia gram of the l ungs , see

35

Fi gure 2- 1 2 . The Pes-V di agram p lays an i mportant rol e i n l ung function exami nat i on . For deta i l s we refer to rel evant l i terature (Buytendi j k , 1949 ; Mead , Mc i l roy , Sel vers tone et al . , 1955 ; Donl eben , 1959 ; H i l ve ri ng , 1963) and the "Handbook of Phy s i ol ogy" { 1964) ed. by Fenn and Rah n . For a d i s ­cuss i on i n connecti on wi th voi ce product i on , we refer to the publ i ­i ca t i ons o f van den Berg ( 1956 ) and Bouhuys ( 1966 ) .

Du ri ng a compl ete respi ratory cycl e a l oop i s formed wh i ch i n norma l l ungs resembl es an el l i ps , see Fi gure 2-12A. I n such a case the mechani ca l funct i on of the l ungs can be approached wi th a s i mp l e el ectri c ana l ogue , con­s i s t i ng of a condenser wi th a con­stant capaci ty C i n seri es wi th a cons tan t res i s tance R . The con­denser represents the compl i ance of the l ungs , the el ectri cal re­s i s tance the v i s cous res i s tance , see Fi gure 2- 128 .

For C , the comp l i ance , app l ies :

c �v ( 2- 5 ) - �Pes i n wh i ch 6V is the change i n vol ume i n a spi rometer connected to the l ungs ( th e change i n the l ung vol ume is then -�V ) and 6pes i s the correspond i ng change i n the pres sure in the oesophagus , as

36

observed i n very s l ow i nsp i rati on and exp i ra t i on .

For normal l ungs C � 2 . 5 l i ter/kPa (0 . 25 l i ter/cmH20 ) ( Buytendij k , 1949 ; Stead , Fry , and Ebert , 195 2 ; Mars ha l l , 1964 ; Spel l s , 1969 ) .

The compl i ance i s pri ma ri l y re­s pons i b l e for the s l ope of the l oo p and can be ca l cu l a ted from i t .

For R , the v i s cous res i s tance , Formu l a 2-6 appl i es :

Rtotal � Rai rways + Rti s s ues ( 2- 6 )

Rti ssues i s about 20% o f Rtotal ( Marshal l and Duboi s , 1956 ) . The res i s tance of the upper a i rways , i .e . from the voca l fol ds to the l i ps , i s about 25% of the tota l res i s tance ( Ferri s , Opi e , and Mea d , 1960 ; Hyatt and Wi l cox , 1960 ; Schi ratzky , 1964 , 1965a , b ) .

The total res i stance varies between 0 . 13-0 . 33 kPa . s/ l i ter ( 1 . 3- 3 . 3 cmH20 . s/l ) , wi th a mean val ue of 0 . 23 kPa . s/ 1 ( 2 . 3 cmH20 . s/l ) (Mc l l l roy , Mead , Sel ve rs tone et al . , 1955 ; Ferri s , Mea d , and Opi e , 1964 ; Ma rshal l , 1964 ; F i sher , Duboi s , and Hyd e , 196 8 ; Spel l s , 1969 ) .

The vi scous res i s tance i s re­spons i b l e for the wi dth of the l oop and i ts va l ue may be computed from i t . When i nspi ration and exp i rat i on

P.,

tension

_6? _ _ _ _ 1r -- - - - - - - -

_ . · I .. .. .. .. I

• • • I

A B c

Figure 2- 1 2 . The pes

-V diagrams :

A . Schematic representation of the pes

-V diagram . At ins�iration the

oesophageal pressure becomes more negative (see also Figure 2-9 ) .

B . Electric analogue model of the lungs , consisting of serial RC cir­

cuit with capacity C and resistance R. The capacitor represents the com­

pliance of the lungs , the resistor the viscous resistance , and the ten­

sion ( voltage ) the effective lung pressure producing inspiration or ex­

piration . As the inptlt voltage varies , the current through the netv1ork

varies out of phase with the voltage .

c . As a res ul t of the phas e shift , the maximum pressure pmax

will be

reached earlier than the maximum volume Vmax

and its corresponding

pressure pc

. The volume Vmax

will be reached when the direction of the

flow changes ( i . e . when the air flow is zero ) . Practically , the di f­

ference between pmax

and pc

is mostly small and depends on the magnitude

of the viscous resistance and the respiratory frequency . In experiments

pc

is used as reference pressure for the determination of the subglottic

pressure , see 2 . 7 .

are very s 1 01·1 , the correspondi ng changes of pressure can be ne­gl ected and the wi dth of the l oop is zero .

W i th s i nuso i da l pressure chan ges the extreme pressure val ues a re reached somewhat earl i e r than the eAtreme vol ume va l ues , Fi gure

2- 12C . Th i s i s caused by a phase sh i ft . When the vol ume has rea ched i ts extreme val ue the fl ow i s zero . The pres sure i s then Pc • wh i ch i s re l a ted to the compl i ance o f the l un gs . The di fference beb1een Pmax and pc i s genera l l y sma l l , pa rtly because the pressure change i s not

37

s i nusoi dal . The reversal of the fl ow occurs rather s l owly in q u i et breath i n g , thus fl atten i n g some­what the pres sure c urve . Moreover , the press ure c urve shows fl uctu­ati ons because the pumpi ng heart rhythmi cal l y e xerts forces on the t i s s ues surroundi ng the bal l oon . Th i s makes i t necessary to use mean va l ues for the pres sures .

The pri nc i p l e of the method to deri ve the s ubgl ott i c pres s ure from the oesophageal pres sures , i s i nd i cated i n Fi gure 2- 13 .

When the vol ume a t t ime t0 pas ses the va l ue Vmax ' the correspondi ng press ure in the oesophagus is Pt , w i th 0

( 2-7 )

Pc i s the press ure due to the com­pl i ance , Ps is the s ubg lotti c pres s ure and Pr i s the product of the v i s cous res i stance and the a i r f l ow rate during phonat ion .

The term pr must be taken as a correcti on facto r , wh i ch i n most cases may be negl ected . However , i n cases of h i gh fl ow val ues , negl ect i ng pr may i ntroduce a sys­tema t i ca l error .

For a fl ow of 200 ml /s , Pr i s comparab l e wi th the random meas ­uri ng error for subg l ott i c press ­ure , i . e . about 5 0 P a ( 0 . 5 cmH20 ) .

38

Correspondi ngly , the s ubglott i c pressure can b e ca l cu l ated at the moment the vol ume curve pas ses Vmi n ' By i nterpol ati on the s ub­g l otti c pressure can be cal cu l ated for every vol ume between Vmax and vmi n '

I n ca l cu l a t i n g , there sti l l are a few potentia l sources of error , wh i ch , however , appea r to be of l i tt l e importance : --

a . I n Equat i o n 2-7 no correction has been made for the res i s ­

tance of t h e fl owhead . The res i s ­tance of the fl owhead ( 2 . 4 . 1 . 2 ) i s 32 . 5 Pa . s/1 ( 0 . 325 cmH20 . s/1 ) . The error due to th i s res i s tance i s proporti ona l to the a i r f l ow rate and negl i g i b l e smal l .

b . I f the pres sure i n the l ungs is i ncreased the l ung vol ume

i s compres sed a nd some �later vapour condenses . If at a l ung vol ume of 3000 ml the pressure is ra i sed from 100 kPa to 100 kPa + �p. the fol ­l owing Equation appl i es for the new val ume V

2 (1QQ - 6 . 3 ) X 3QQQ 100 ( 100 + �p - 6 . 3 ) 2

X V 100 + �p

From th i s Equati on

(2-8}

V = 3000 - 34 x �p ( 6 . 3 kPa is the satura ted vapour pres sure at 37 °C ) . The l ung vo l ume i s sma l l er and th i s

respirat ion phona t io n

-----7 t

Figure 2- 1 3 . Principle of calculating subglottic pressure during pho­

nation . At time t0

after the onset of phonation the value Vmax

is reached

again . The pressure pc

' corresponding with volume Vmax

' should then be

regi stered , if phonation had not begun . The actual pressure in the

oesophagus at time t0

is pt0

• The dif ference beb1een pt0

and pc

corre­

sponds wi th the subglottic pressure during phonation ps

' plus a pressure

pr

which equals the product of the viscous resis tance and the air floH

rate during phonation . The pressure pr

is negligible in normal lungs .

Potential sources of error have been discussed al ready in the text.

goes a l ong wi th a somewhat h i gher oesophageal pres s ure . Th i s error is proporti onal to the l ung vol ume and the subgl otti c pressure . At a l ung vol ume of 3000 ml before the compres s i o n , the vol ume oecomes 34 ml smal l er after compress i on at

a s ubg l otti c press ure of 1 kPa ( 10 cmH20 ) . W i th a compl i ance of 2 . 5 l /kPa the measured subgl otti c press ure woul d be 14 Pa (0 . 14 cmH20 ) i . e . 1 . 4'' too h i gh . Th i s may be negl ected .

c . At ra i s i ng the subgl otti c

39

TIME (s)

VOLUME (I)

ESOPHAGEAL PRESSURE (kPa)

AIR FLOW RATE (I/s)

i ll

' I

).,}\ Figure 2- 1 4 . Verification of the indirect measuring method by abruptly

stopping phonation . For a short moment after phonation the lung volume

is kept constant with an open glottis . The pressure in the oesophagus

drops to the value pc

corresponding with that lung volume . The pressure

drop 6p equals ps

+ pr

( Figure 2- 1 3 ) . In calculating 6p, it is necessary

to take account of the variations in consequence of cardiac activity .

press ure some bl ood wi l l be pressed out of the l ungs and t h i s may have some i nfl uence o n the compl i ance and the v i s cous res i s ­tance . Th i s error wi l l be proporti ona l to the s ubgl ott i c pres s ure , b u t i s probably sma l l .

40

2 . 7 . 2 Veri fi cati on o f the i nd i rect method for determi ni ng subgl ott i c pressure

The method described can be veri fi ed as fol l ows : - -

a . By abruptly s topp i ng phonat i on and keeping the g lott i s open ,

ma i nta i ni ng the l ung vol ume con-

TIME (s)

VOLUME (I) os(_"._ /---:/:+-:------------- � __ � 1.01 \.._/ .... -------

SUBGLOTTAL ------���--���� PRESSURE (kPa) O.S " p 1 '

0.0 - --·-t--- 5 ----------ESOPHAGEAL �---.r-.r �-·· . .,-.. -.--

PRESSURE (kPa)-g�1 .\�/ · -.�\--..;···-� Ps '\____r:� ,

AIR FLOW RATE 0/s)

SOUND INTENSITY (dB)

0.3l Q2 \_ 0.1 0.0

:�l �� - -- -- �--�---+---"""-- --Figure 2- 1 5 . Verification of the indirect measuring method by simulta­

neous measurement of the subglottic pressure by a direct method . To

measure the subglottic pressure directl y , a hollow needle connected with

a pressure transducer is inserted into the subglottic space .

stant , see Fi gure 2- 14 . The oesophagea l pressure s ha rp ly

drops to the va l ue correspond i ng to that vo l ume . The pres sure drop �p . equa l s the s ubg lott ic pressure duri ng phonation pl us Pr ·

The res u l ts of th i s method -whi c h only can be appl i ed wi th tra i ned subjects - y ie l ded s a t i s ­factory agreement between t h e tv1o methods , s i nce dev iat ions rema i ned wi th i n meas uri ng errors .

b . By compa r ing the ind i rect ly meas ured s ubgl ott i c pressure

wi th the s i mul taneous di rectly

measured s ubgl otti c pres sure . Such a compa rison cou l d be

carri ed out in three pat i ents . The cr i cothyroi d membrane was per­forated by a ho l l ow need l e ( 18 gauge , Angiocath , Deseret Pharma­ceuti cal Co . , I nc . , Sandy , Utah 84070 , USA ) , the t i p of the needl e be i ng brought i nto the s ubgl ottic space . The need l e was connected to a pres sure transducer by mea ns of a catheter .

The res ul ts of 106 compa ri sons are s hown in Fi gure 2-15 and Fi gure 2- 16 . The l i nea r regres s i on l i ne

4 1

2.5 y

INDIRECT Ps (kPa)

2.0

lineair regres sion Y=0.985 X + 0.055 rxy = 0.99 n=t06

1.5

1.0

0.5

0.5 1.0 X

1.5 2.0 2.5 DIRECT Ps (kPa)

Figure 2- 16 . Comparison of subglottic pressure values , simultaneously

measured with a direct method and with ou� indi �ect method in th�ee

patients .

i s assoc i a ted wi th a corre l at ion coeffi c i ent of 0 . 9 9 . The s h i ft of the l i ne corresponds w i th a sys­tema t i cal error of about 50 Pa ( 0 . 5 cmH20 ) , correspondi ng wi th the expectati ons based on negl ect i ng the pressure Pr ·

2 . 7 . 3 Automa t ic correct ion for

for automati c correcti on for the comp l i a nce of the l ungs was de­s i g ned and bui l t i n the Gro n i ngen Uni vers i ty Laboratory for Medi cal Phys i cs .

Mead and Wh i ttenberg ( 1953 } had previous l y i ntroduced a method for comp l i a nce correc t i o n . Th i s method we have impl emented for our

the comp l i ance of the apparatus us i ng an adj ustab l e l un gs constant fraction of the vol ume

s i gnal to i nversely contro l the Duri ng our i nvesti gat ion a dev i ce pressure s i gna l , s ee F i gure 2-17 .

42

'

esop pre hagea l ssure

volume signal

adjustable ampl i f ier 1ao• fase shift

summation amplif ier

corre cted age a I sure esoph pres

Figure 2- 1 7 . Diagram of the set up for the automatic correction method

used for the lung compliance .

A B c

vinsp_

dr i ft

Figure 2- 1 8 . Diagrams of pe5

-V loops demons trating the effect o f the

correction methods .

A . 1'/i thout correction

B . With expiration flm1 correction ( 2 . 5 . 2 . 2 )

C . \'lith expiration flm1 correction and compliance correction ( 2 . 7 . 3 ) .

I t may be assumed that the com­pl i ance is cons tant wi th i n the range of the vol umes , provi ded that

duri ng the measurements the person nei ther i nsp i res nor expi res too deepl y . At the l evel of Vmax ( i . e .

43

TIME(sl

�� W Mil���-------- · - � (B) ��l - -�-------------

ESOPHAGEAL -asl PRESSURE (kPal 001

(A) -0.5 -ID

AIR FLOW 0.0211

RATE (1/sl O:Ol

Figure 2- 19 . Effect of the automatic compliance correction during res­

piration. The curves were registered in a subj ect asked to expire s lowly

after an inspiration . Curve A shows the directly represented variations

of oesophageal pressure , while the simultaneously obtained oesophageal

pressure curve after the automatic compliance correction ( 2 . 7 . 3 ) was

recorded in curve B .

The variations in curve A are mainly due to changes related t o the com­

pliance . The remaining variations in curve B are the consequence of the

viscous resis tance and the momentary value of the air flow rate . The

running mean values of the pressure during the respiration shown in curve

B represents a zero subglottic pressure . This zero value may also be

obtained by holding the breath with an open glottis , the corrected

pressure in that case will represent zero .

the Functional Res i dual Capaci ty l evel ) the comp l i ance curve i s l i near. The fraction o f the vol ume s i gnal needed for proper correction has to be determi ned experimenta l ly for every i ndi vi dua l pers o n . The i ndi vi dual va l ue of the comp l i a nce can be der i ved from the va l ue of the requi red fract ion .

When the adj ustment i s correct the l oop i n the Pes-V d i agram wi l l

44

be verti cal , see Fi gure 2- 188 and C . The corrected oesophageal press­ure wi l l then show only sma l l vari ati ons due to the v i scous re­s i s tance and wi l l be proportional to the momen ta ry va l ue of the a i r fl ow ra te , s ee Fi gure 2- 1 9 . After proper adj ustment the corrected oesophageal pressure wi l l rema i n a t a constant l evel duri ng qu i e t brea thi ng .

TIME (s)

VOLUME (I) osJ�,_ (8)

ESOPHAGEAL PRESSURE (kPa) ODl

(A) OS 1.0 041 AIR FLOW 02 \\ RATE (I/s) 0.0 . .....,.�..\

SOU NO :l INTENSITY (dB) 70 60

RESPIRATION

-.'I ! 'J ' \1\ ,, J I

PHONATION

,•

\ v--

-� /'\ I �·

J

Figure 2-20 . Effect of the automatic compliance correction during pho­

nation . The curves were recorded in a subject asked to phonate after a

few quiet respirations . In this Figure ps

has been de termined at time

t0

( neglecting the vi scous resistance ) to compare with p 's

, i . e . the

subglottic pressure determined at the same moment from the corrected

pressure . From the automatical ly corrected pressure curve the subglottic

pressure can be read at each moment during phonation .

Duri ng phonat i on the pressure i s i ncreased by an amount wh ich equa l s the correspondi ng subgl otti c pressure , see Fi gure 2-20 . The errors di s cussed under 2 . 7 . 1 may of course p l ay an add i t i onal ro l e .

The automati c correction grea tly s impl i fied the el aborat ion of the curves , as the s ubgl otti c pres sure duri ng phonati on i s s i mp ly equal to the i ncrease in the corrected oesopha gea l press ure .

Dri ft duri ng phonation i s recog­ni zed i mmed i ately from the l evel

of the corrected pressure in q u i e t breathi ng before a n d after phonation .

Si nce the automatic correction dev i ce was cons tructed duri ng the l a s t phase of our i nvest i gation , nearly al l subgl otti c pressures were determi ned by the method descri bed i n 2 . 7 . 1 .

45

Chapter 3 Analysis of curves and processing of experimental data

3.1 Introduction

I n mos t cases the measurements were performed after the subjects had fi rst vi s i ted our outpa ti ents department , where a s ubject pro­tocol was taken down based on gen­eral observat ion and mi rror exam­i nat ion , sometimes i ncl uding s tro­boscopy . Before the meas uring series was s ta rted , thus data were ava i l a b l e i nter al i i about the s ubjects vocal potenti al i t i es ( phonetogram) and average spea k i ng vo i ce pi tch l evel .

Mos t ly at the end of an exp i r­at ion , the subject was a sked to ta ke a breath and to start pho­nati o n . The requi red pi tch was i nd i ca ted , s tarti ng wi th a pi tch and a sound i ntens i ty that cou l d be eas i ly produced by the subject . When the enti re i ntens i ty range of al l pre-sel ected pi tches has been exami ned , the measuring equ i p­ment was checked .

Before the automa t i c correction for the compl i ance was avai l ab l e , the curves were graphi cal ly e l ab­orated . The pri nc ip le of th i s method has been di scussed i n 2 . 7 . 1 and i s i l l us trated by F i g ure 3- 1 .

Gra ph i c el aborat ion of the c urves is not pos s i b l e during th� meas ­uri ng seri es , a s i t takes qui te some time and therefore has an

46

i nh i b i ti n g i nfl uence on the prog ress of the measuring seri es . W i th the automat ic correction of the oesophageal pressure for the comp l i ance of the l ungs , the data can be taken from the curves during the s eri es and eventual ly fi l l ed i n i n a graph . I f des i red , a dd i ­ti onal measurements a t any pi tch and i ntens i ty coul d be carri ed out i mmediatel y .

The rejection of curves i napt for use wi l l further be di scus sed in 3 . 2 .

The determi nati on of experimental data wi l l be descri bed in 3 . 3 .

I n 3 .4 the process i ng o f the data and ca l cul ation of the effi c i ency wi l l be descri bed .

Fi na l l y the presentation and compari son of measuring resul ts wi l l be di scussed in 3 . 5 and 3 . 6 .

3.2 Rejection of curves

Sometimes curves had to be re­jected as not usabl e to determi ne the subgl ottic pressure , e . g . i n the case o f a contraction o f the oesophagus .

The curves sometimes show de­vi ations in consequence of var ious condi ti ons . These ought to be re­cogni zed at the time of the meas­uri ng seri es , so tha t , if an ar­tefact occurs , the phonation can

TIME (s) l Vmax VOLUME (I) 0.5 ! .'-_/

ESOPHAG EAL PRESSURE (kPa)

AIR FLOW RATE (I/s)

SOUND INTENSITY(dB)

0.0 0

.51 -0.5 .._.,;-� ,, U4l 0.2

0.0 90l 80 70 60

to

� I I /Jt � I 1 \�,

I \ \ I q

I

Figure 3- 1 . An example of an usable registration, wi thout correction

for the mechanical properties of the lungs . The point of time t0

and the

reference oesophageal pressure pc

are ascertained by reference to Vmax '

The difference bet�1een the oesophageal pressure a t the time t0

and the

reference pressure pc

is the subglottic pressure ps

{ neglecting pr

) . For

the same point of time , the sound intensity I and the mean air flow rate

q are determined .

be repeated at the same pi tch and i n tens i ty . The frequency of arte­fac ts per seri es va ries and i s un­pre d i c tabl e .

The i nsert i on o f the ba l l oon may i nduce contracti o ns of the oesoph­agus , but for the mos t pa rt these subs i de after a s hort t ime , per­mi tti ng an usab l e curve to be

obta i ned . I n F i gure 3-2 four exampl es are

represented of not usabl e reg i s ­t rati ons .

a . F i gure 3-2A . Wi thout compl i ance correcti on .

Here , the subject i nspi red too sha l l ow to pass the po i nt vm i n a n d then s topped phonation before

47

poi nt Vmax was reached . I n such cases , i ns tructi ons were g i ven and the phonation �1as repeated .

b . Fi gure 3-28 . Wi thout compl i ance correction .

Jus t before phonation the s ubj ect had swal l owed. The a i r passage was bl ocked for a short ti me ( no fl ow ) and after that a powerful con­traction of the oesophagus fo l ­l owed , ma k i ng the pres sure cu rve not usabl e duri ng a 7 s econds i nterval .

c . Fi gure 3-2C . Wi thout compl i ance correcti on .

Here , the pres sure curve s hows the effect of the presence of a i r i n the oesophagus . Duri ng qu iet breath i ng the oesophageal pres sure va r ies beb1een 1 i mi ts determi ned by the mean res t i ng press ure i n the oesophagus (wh i ch i s negati ve ) , the compl i ance of the l ungs and the t i dal vol ume . When the refer­ence oesophagea l press ure Pc ( F i gure 3- 1 ) has been determi ned , Pc shou l d b e wi th i n these l imi ts . A devi ati ng va l ue may be the res ul t of an increased mean res ti ng pressure in the oesopha gus , caused by the pres ence of ai r in the oesophagus . The person wi l l notice this as such . The a i r can be made to es cape by deep s i gh i ng or be l ch i ng .

48

d . F igure 3-20 . W i th and w i thout compl i ance correc t i o n .

Here , a press ure artefact i s shown duri ng phonat i on . A certai n course of the curves can be ex­pected . For examp l e , i n phonation wi th a constant sound i ntens i ty and a constant fl ow , the oesoph­ageal pressure wi l l s l owly i n­crea s e . Sometimes duri ng phonation an eas i ly recogn i zab le l i ttl e contraction of the oesophagus occurs . In Fi gure 3-20 th i s hap­pened just at the moment for de­termi ni ng the reference pres sure Pc · The curve wi thout correct i on for the compl i ance cannot be el ab­o rated . The advantage of the cor­rected oesophageal pres sure i s obvi ous . The phonation can b e used for the periods before and a fter the contracti o n .

3.3 Collection of data

For the el aboration of the curves a s tandard protocol is used . Wi th the a i d of cal i brated sca l es , the data for a i r fl m� ra te , subg l otti c pres sure , and sound i ntens i ty can be read wi thout convers i on .

The readi ng prec i s i on for the sound i ntens i ty i s � 0 . 5 dB , for the a i r fl ow ra te + 2 . 5 ml/s and for the oesophagea l press ure + 25 Pa ( 0 . 25 cmH20 ) .

A t

(s)

0.5] Pes 0.0

(kPa) ·0.5

Vmin

u1s1 0.2 � r

ODj

Vmax

\ , I

I ��j (dB) 60�----

t (S) B SWALLOW CONTRACTION

v os:l (I)

t (S) c v o.s;l (I)

OS] Pu 0.0

(kPa) ·0.5

q (lis)

80] I 70

!dB) 60

t (s) D v

(I)

corr. P.,

lkPa)

P., lkPa)

q (lis)

I (dB)

Figure 3- 2 . Examples of curves not usable for elaboration , see text .

Taki ng i nto account the fl uc­tuati ons of the curves , the measured val ues for the i ntens i ty are rounded off to mu l ti p l es of 1 dB and thos e of the fl ow to mul t i p l es of 5 m l/s .

I n determi ni ng the data for the oesophageal pres s ure , the rhythmi c va r i a t i ons as a resul t of card i a c acti v i ty mus t b e taken i nto

account . Therefore a mean va l ue i s assessed and taken down i n mu l ti pl es o f 50 Pa ( 0 . 5 cmH20 ) .

3.4 Processing of data.

Calculation of efficiency

The measured val ues for a i r fl ow rate , subgl otti c p ressure , and i ntens i ty , together 1·1 i th the va l ues

49

for the pi tch and the avera ge speak i ng vo i ce pi tch l evel , a re transferred to a computer system for fu rther proces s i ng . For every seri es some admi n i s t rati ve i tems a re added . By us i ng the computer the ca l cu l a t i on of the effi c i ency i s eas i e r and the resu l ts can be compared wi th each other and wi th reference val ues .

Catculation of efficiency .

The effi c i ency E of the gl otti s generator i s ca l cul ated by re l at i ng the produced sound power , Pacoust ' to the subg lotti c power suppl i ed to the l a rynx , Ps ubgl . Represented in a formul a :

E _ pacous t - psubgl

( 3- 1 )

For the cal cul ation o f the pro­duced sound power Pacoust we s tart from an approxima tion , a l ready menti oned i n 2 . 3 . 2 .

The subgl o tti c power Ps ubgl i s ca l cu l ated by mu l ti plyi ng the mean air flow rate by the mean s ub­g lotti c pres sure .

A numerica t examp te .

Gi ven : an i ns ta nce of phonati on wi th a sound i n tens i ty I of 7 5 dB measured at a di s tance r of 15 em

50

i n front of the outl et of the f l ow­head , the a i r fl ow rate q be i ng 200 ml /s , the subgl ott i c pressure p bei ng 1 kPa ( 10 cmH2D ) .

I P 2 2 10

10 X 10- 12

acoust = x rr x r x

Ps ubgl

2 X IT X (0 . 15 ) 2 m2 X

X 107 . 5 X 10- 1 2 -.;. m

4 . 47 x 10-6 Watt

� 4 . 5 X 10-6 Watt

q X p 3

200 c� x 3

2 . 10-4 ms x

2 10- 1 x Nm . s

0 . 2 Watt

kPa

Then , subst i tuting these val ues i n Equation 3 - 1 , we may wri te

-6 E =

4 . 5 X 10 2 X 10- 1

= 2 . 25 X 10- S

Th i s numerical exampl e can be extended by an analys i s of the propagation of errors in the cal ­cul at ion of the effi c i ency .

I f Z i s the product ( or quoti ent) of A and B, and 6A i s the error i n A , 6B the error i n B , the error

Table 3- 1 . Experimental data obtained from a normal male subj ect for air

flow rate and subglottic pressure at various sound i ntensities measured

at a pitch of E3 ( 165 Hz) . In the last column , the calculated efficiency

values have been given . The dynamic range was 28 dB . The average speaking

voice pitch level was C3 ( 1 25 Hz ) . The number of measured data was nine ,

and the calculated regression lines are represented in Figure 3-4 .

i ntens i ty mean fl ow mean I in dB q i n m l /s

60 90 64 95 64 120 70 180 73 165 78 200 79 220 88 380 38 450

!JZ sat i sfi es

The subgl ott i c power Psubgl i s the product o f the mean fl ow and the mean pres sure ,

( ": ::::; )' 0 ( ":)' ' ( ·;)' (�J + (16�or

0 . 0282

p i n

Thus , the percentage error may be sai d to be about 3 .

s ubgl . press u re eff i c i ency kPa ( 10 cmH20 ) E i n xlO -5

0 . 25 0 . 6 0 . 25 1 . 5 0 . 25 1 . 2 0 . 35 2 . 2 0 . 3 5 . 7 0 . 5 8 . 9 0 . 6 8 . 5 0 . 8 29 . 3 1 . 0 19 . 8

The percentage error i n Pacous t i s due to the i naccu racy of meas­uri ng sound i ntens i ty . A vari at ion of + 0 . 5 dB means a vari at ion of + 12% .

The percentage error i n the effi c i ency is thus

ll� + Vo . 122 + o . 52

+ 0 . 13 or 13�

The error i n the fi na l resu l t i s ma i nly determi ned by the sound i nten s i ty measurement error . At l ow subgl otti c press ures , e . g . 0 . 5 kPa ( 5 cmH2o ) the error i n the

5 1

effi c i ency runs to about 15% .

3.5 Presentation of data;

regression lines

A measuring series general l y i s composed o f 40-50 phonati ons , d i s ­tri buted over various frequenci es .

For every phonati on a t a certai n freq uency and s ound i ntens i ty , the experimental data for a i r fl ow rate and s ubglott i c press ure are g i ven i n m l / s res p . kPa . The cal cul ated effi c i ency is gi ven in 10-5 , see Tabl e 3- 1 .

Because of the presence of random devi a t i ons the raw experimental val ues cannot be used very wel l for compa ri son wi th reference va l ues or for compari son of resu l ts of several meas uri ng series wi th each other . I n order to el imi na te these random dev i a t i ons as much as pos s i b l e , the data o f a group of phonati ons , e . g . for the same pre- sel ected freq uency , were processed i n a s catter d i agram . On the hori zonta l a x i s �1e fi nd the sound i ntens i ty and , on the verti cal ax i s , the a i r fl ow rate , s ubgl otti c press ure , or effi ci ency .

The sound i ntens i ty on the X-ax i s i s ta ken a s the i ndependent vari ­abl e and the va l ues represented on the Y-axi s as the de pendent

52

vari abl es . The rel at ion between the va ri ­

abl es can be descri bed by computi ng a curve through the mea s uri ng poi nts .

From our own prel i mi n a ry studi es and from the l i terature ( Van den Berg , 1956 ; Koi ke and H i rano , 1968) it appeared that the rel a ti on can be descri bed fa i rl y wel l by a stra i ght l i ne i f the l ogari thms of the dependent vari ab l es are used .

The computi ng of the c u rves i s therefore restri cted to the deter­mi nation of the bes t fi tt i ng stra i ght l i ne through the experi ­mental data . Such a l i ne usua l l y i s cal l ed a regress i on l i ne .

The val ues o f the i nten s i ty wi l l be i ndi cated as x ; the transfo rmed va l ues of fl ow , press ure , or effi ency as y, see Fi gure 3-3 . The Equat i on for the regres s i o n l i ne i s then : Ye = a + bx ( 3- 2 ) i n wh i ch Ye ( s t i mate ) i s the best estimate of the transfo rmed va l ue , x i s the i ntens i ty va l ue i n dB (wh i ch in i tsel f is al ready l ogari thmi c ) .

The coeffi c i ent a determi nes the hei ght of the l i ne , whi l e the val ue of a can be read from the po i nt of i ntersecti on of the regre s s i on l i ne and the Y-ax i s .

The regress i on coeffi c i ent b represents the s l ope of the l i ne ; v a pos i ti ve val ue of b mea ns an i nc rease { for exampl e of the s ub­g lotti c press ure) at i nc reas i ng i ntens i ty .

I f the val ues of a and b are known , an estimate can be made of the flow, subgl o tti c pressure , or effi ci ency at a certai n i nten-s i ty by cal cul ati ng the corre-spendi ng va l ue of ye wi th Equat i on 3-2 .

The determi na t i on o f the best fi t t i ng stra i gh t l i ne th rough the expe ri mental data , wi th the ca l cu­l a t i on of a and b, is based on the l eas t-squares method descri bed i n manua l s on stati stics ( Armore , 196 7 ; Snedecor and Cochran , 1968 ; Bevi ngton , 1969 ; Saka l and Roh l f , 1969 ; Wyve kate , 1972) . The re­gre s s i on l i ne i s computed in such a way , tha t the s um o f the squares of the i nd i v i dual dev i a ti ons from th i s l i ne i s m in imal .

The res i dual spread i s repre­sented by the so-ca l l ed Estimated Standard Dev i a t i on of Error , short e . s . d . e . Thi s measure denotes the d i s pers i on around the regres s i on l i ne .

After the transformat i on and the cal cul at ion the experi mental data and the regre s s i on l i ne are d i s ­pl ayed graph i ca l ly wi th a computer

0

Figure 3-3 .

Determination of the regressior

line : the best fitting straight

line drawn through a number of

measured data . The line is defined

by the formula ye

= a + bx , in

which a indicates the height of

the line and b the slope of the

line , i . e . the tangent of the angle

of inclination S. The line has been

computed in such a way that the

sum of the squares from the dis­

tances d, the vertical distances

from the measuring points to the

line , is minima l .

control l ed X-Y recorde r , and the va l ues of a , b , and e . s . d . e . are pri nted out .

The regres s i on l i ne i s only ap­pl i cabl e for i ntens i ty val ues �li th­in the dynami c range of the vo i ce at a certa i n frequency . Therefore ,

5 3

X

0 100

E( 10"')

10 0

0

1

0. I e

6 � :......-�

/ � . / v

/ .h;' v �

70 so

Figure 3- 4 .

90 100 ! (dB)

1.0 q{l/s)

0 5

0.2

0 1

0.05

1 0 p (kPa)

5

0.5

0.2

0.1

Regres sion lines for the experi­

mental data given in Table 3- 1 .

i n pl otti ng the regress i o n l i ne only that part of the x-ax i s i s used wh i ch corresponds wi th the dynam i c range of the vo i ce . Extra­pol a ti on outs i de th i s range i s mean i ngl es s .

The regress i on l i ne i s regarded as an average of the measured va l ues , see F i gure 3-4 . I n th i s fi gure , the experi menta l data and the corres pondi ng regress i on l i nes are dep icted for the data of Tab l e 3- 1 .

54

3.6 Comparison of data with

the aid of regression

lines: characteristic values

for the middle of the

intensity range

The regress ion l i nes a re es­pec i a l l y useful for compari ng the resul ts of several d i fferent 1t measur ing seri es .

I n Tabl e 3- 2 , experimental data a re g i ven as obta i ned i n exam i n i ng a pati ent . Fi gure 3-5 gi ves the regress ion l i nes together with the correspondi ng reference regres s i on l i nes as obtai ned for normal sub­jects , see Chapter 4. For the en­ti re dynami c range , the flow re­gres s i on l i ne as wel l as that of the subgl otti c pressure l i es at a hi gher l evel tha n the reference regress ion l i ne . Consequently , the effi c i ency regress i on l i ne l i es below the reference regress i on l i ne for the enti re dynamic range .

I n compa ri ng effi c i enc ies of various vo i ces at i denti cal i nten­s i ty val ues , on pri nci pl e a com­pari son i s made of the val ues of the subgl otti c power supp l i ed . I t i s common practi ce to use the decibe l measure for a compa rison of power val ues .

By us i ng a deci bel di v i s ion a long the Y-ax i s , the di fference wi th another effi ci ency regres s ion l i ne

Table 3- 2 . Experimental data obtained from a female patient for air flow

rate and subglottic pressure at various sound intensities measured at a

pitch of A3 ( 220 Hz ) . In the last column , the calculated efficiency

values have been given. The dynamic range was 25 dB . The average speaking

voice pitch level was A3 ( 2 10 Hz) . The number of measured data was 19 and

the calculated regression lines are represented in Figure 3-5 .

i ntens i ty I i n dB

63 64 66 6 7 68 70 7 1 7 3 74 74 74 75 76 77 78 78 80 84 88

mea n f l ow q i n ml /s

340 180 250 3 70 200 410 325 300 300 4 10 375 470 440 450 390 360 330 3 50 520

at a certa i n sound i nten s i ty may be read di rectly i n decibe l , see Fi gure 3-6 .

I n compa ri n g regress i on l i nes wi th each other and w i th the cor­respondi ng reference regress i on

mean subgl . pressure p i n kPa ( 10 cmH20 )

0 . 95 0 . 8 0 . 95 1 . 25 1 . 1 1 . 6 1 . 1 1 . 0 1 . 1 5 1 . 2 1 . 2 1 . 1 1 . 2 1 . 3 1 . 25 1 . 5 1 . 55 1 . 55 2 . 1

eff i c i ency E i n x1o-5

0 . 1 0 . 2 0 . 2 0 . 2 0 . 4 0 . 2 0 . 5 0 . 9 1 . 0 0 . 7 0 . 8 0 . 8 1 . 1 1 . 2 1 . 8 1 . 7 2 . 8 6 . 6 8 . 2

l i ne , i t i s mean i ngful to compa re the data for the i ntens i ty va l ue rm bel ongi ng to the m idd le of the dynami c range , as it may be a s s umed that the val ues for a i r fl ow rate , subgl otti c pres s u re , and effi c i ency

55

A I

.. ..

- · _ ;... --

..

-p Ql

� f--

..... I

100

••

.. 10

B

- · · - !.--;--. .

I

I

y v.;

0 100 1!(10 ' I

10 0

0

I

- - - - - - -

. . _./

c

/ fi� / /

/ I / I _ _ ./ I ... -/ v .. /

I 70 00 '·

AIR Flo.l RATE ( 1/s ) 7 5 . 5 dB

qm • 0.36

Ref.value = 0 . 185

• J . Q9 7 X 10-2

Ref.value • I . 15 x 10-2

I 1

[(dOl : '·

SUBGLOTTIC PRESSURE ( kPa)

Im • 75.5 dB

1 . 32

Ref.value = 0.6

• J . I9B X 10-2

Ref.value = 2 . 5 .w. 10-2

I I

70

EFFICIENCY (x I0-5)

7 5 . 5 d8

1 . 1

Ref.value = 4 . 6 1

• 7 . /04 X 10"2

Ref .value = 6 . 3 x 10-2

'"""

Figure 3-5 . Depiction of the method for comparison of measuring results

with the aid of regression lines . For the sake of clarity , the data for

flow , pressure , and efficiency are each represented separately in a

diagram ; in mos t cas es , in this work , these data are all represented in

the same figure . The experimental data used for determination of the

regression lines of the patient were recorded in Table 3-2 . The reference

values belong to an intens ity in the middle of the dynamic range { Im

) '

see Chapter 4 , Figure 4- 1 2 .

56

at Im a re i n general representa t i ve for vo i ce product i o n .

The dynamic range a n d i ts mi ddl e are a l so pl otted by the computer in the tab l es . The ca l cu l ated va l ues for ai r fl ow rate , sub­gl ott i c press u re , and effi c i ency at Im are i nd i cated as qm ' pm ' and Em ' respecti ve ly .

Compari son wi th the reference regress i o n l i ne al ways takes p l ace at the i n tens i ty val ue Im of the i nd i v i dual regress i o n l i ne . For the effi ci ency , the di fference i s recorded as Erel ( i n dB) . The val ues Erel enab l e us to compare i nd i vi dual regress i on l i nes . I n doi ng s o the i nfl uence o f di f­ferences i n Im between the meas­uri ng seri es i s el imi nated i n a fi rst approximati o n .

The di fference between E rel va l ues i s i ndi cated as 6Erel ·

The regress i on coeffi c i ent b , wh i ch dete rmi nes the s l ope of the l i ne , sometimes devi ates only l i ttl e from zero . In the tabl es , the val ue of b = tans ( Fi gure 3-3) therefore i s gi ven a fter mul ti ­pl i cation by a factor 100 .

I n eva l uati ng the res ul t of a gi ven therapy to a pati ent , i t may happen that the dynami c ranges of succes s i ve meas uri ng series are not i denti ca l . In such a cas e , the

,, E, ... I +2 0

+1 0

/

Erel -

-1

0 / /I V I /

6 - -/- - -1.' 0 ; :

/ '

I ' l l l

I 60 70 80

EFF I C I ENCY (x 10-5) Im = 7 5 . 5 dB

Em = 1 . 1

b

Ref . va lue = 4 . 6 1 = 7 . 704 X 10-2

90

/ /

Ere!

I 100

! (dB)

Ref .va lue = 6 . 3 x 10-2

Ere l = -6 . 3 dB

Figure 3-6 .

The re ference regression line for

the efficiency based on the com­

bined experimental data from a

number of normal subjects ( see

Chapter 4) displayed together with

the efficiency regression line from

one patient (Table 3-2 ) . The dif­

ference in efficiency (Erel

l at

a certain intensity can be read

directly in dB .

57

Table 3- 3 . Characteristic values for the experimental data in the middle

of the dynamic range for air flow rate , subglottic pressure , and effi-

ciency as recorded in Table 3- 1 and Table 3- 2 .

number dyn . ra nge Im of data dB dB

FLOW

Normal Subj . 9 60 - BB 74 Tabl e 4- 1 Pati ent 19 63 - 88 75 . 5 Tab l e 4-2

SUBGLOTT I C PRESSURE

Normal Subj . 9 60 - 88 74 Tab l e 4- 1 Pati ent 19 63 - 88 7 5 . 5 Tab l e 4-2

EFFI C I ENCY

Norma 1 Subj . 9 60 - 88 74 Tabl e 4-1 Patient 19 63 - 88 75 . 5 Tab l e 4-2

fact that the dynami c ran ge i s l arger o r sma l l er a l so i s s i g­n i ficant and ought to be cons i dered i n es tabl i shi ng a concl us i on .

Summarizing:

The resu l t of the ca l cul ati ons for the characte ri s t i c val ues a ,

58

b a e . s . d . e . x10-2

qm ml /s

2 . 31 0 . 558 0 . 06 185

1 . 097 1 . 729 0 . 1 361

Pm kPa

2 . 1 75 -1 . 974 0 . 07 0 . 4 3

1 . 198 -0 . 786 0 . 06 1 . 32

Em Erel x10-s dB

5 . 51 5 -3 . 424 0 . 1 4 . 5 0 . 9

7 . 704 - 5 . 784 0 . 13 1 . 1 -6 . 3

b , Im , qm ' pm , Em ' and E rel , and e . s . d . e . are wri tten out by the computer after computi ng the re­gress i on l i nes from the experi ­menta l data .

I n Tabl e 3-3 these cha racteri s ti c va l ues are g i ven for the experi ­menta l data from the Tab l es 3- 1 and 3- 2 .

Chapter 4 Investigation conducted in normal subjects: reference values

4. 1 Introduction

For eval uat i on of experimental data from pat i ents , reference va l ues are requ i red . In order to obta i n such val ues , measurements were performed i n men and women who never had troub l es w i th the i r vo i ces . The meas urements were per­formed i n the same way as i n pati ents .

A survey of the norma l s ubjects is gi ven in 4 . 2 .

I n section 4 . 3 , the reproduc­ib i l i ty of measurements i n the same s ubject is d i scussed .

The set of the regres s i on l i nes from al l normal s ubjects forms a reference area for eva l uati ng the regress i on l i nes of pati ents . These reference a reas for fl ow , pres s ure , and effi c i ency wi l l be d i scussed i n 4 . 4 .

I n 4 . 5 , the res ul ts o n the group of norma l s ubjects are compared wi th data from the l i terature for fl ow , press ure , and effi ci ency .

I n 4 . 6 , the aerodynami cal di f­ferences between breathy and non­devi ant phonati ons i n the same normal subject are di s cussed .

4.2 Survey of the normal

subjects

The group of normal s ubjects

cons i s ted of 30 ma l es and 33 fe­mal es . They were recrui ted from vo 1 unteers : co-�10rkers of the E . N . T . Department , med i cal stu­dents , and students from the tra i n i ng-centre for s peech thera­pi s ts . None of these s ubjects ever had a ny voca l compl a i nts . Laryngeal abnormal i ti es were not observed ; the compass of the voi ce was at l ea s t two octaves .

I n these 63 peopl e , 93 measuring seri es were performed , w i th usab l e sets of curves for 4267 s i ng l e i ns ta nces o f phonation . Phonati ons j udged by trai ned l i s teners to be voca l ly di sturbed , e . g . breathy , hoarse , or hyperki neti c , were d i s ­ca rded . I f l ess than 10 phonations per measuring series were l eft , the whol e seri es was put as ide . Th i s reduced the g roup to 45 normal s ubjects ( 24 ma l es and 21 fema l es ) . I n 4 . 4 . 4 we sha l l d i scuss the aerodynami c characteri st ics of the d i s ca rded phonati ons .

The age of the men va ri ed from 20 to 65 years , a veragi ng 3 1 years . The age of the women ran from 17 to 32 years , averagi ng 23 years . From the 45 norma l subjects 72 usab l e series were obta i ned ; 1 7 s ubj ects came for 2 seri es , 2 for 3 and 1 for 7 seri es .

Tab l e 4- 1A and 4-18 g i ve a survey .

59

Table 4- 1 A . Sub j ect protocols for the 24 normal male subj ects , with

respect to age , number of measuring series , average speaking voice pitch

level ( fmean

) ' and number of phonations in the successive measuring

series . The total number of measuring series was 4 3 , comprising a total

of 19 1 7 instances of phonation at various pi tches and intens ities .

60

Subject No .

1 2 3 4 8

12 13 16 17 18 21 24 25 31 35 38 44 46 47 55 60 6 1 62 63

aoe years

26 3 1 32 3 1 20 22 39 20 24 2 7 20 2 1 20 2 3 30 23 24 36 31 24 56 65 52 47

number of seri es

3 7 2

2 2 2 2 2 2

1 1 1 2

1 2 3

f mean Hz

1 10 1 25 1 10 1 10 100 95

1 30 1 35 1 2 5 100 1 1 0 100 130 1 1 0 120 120 90

130 100 90 9 5 9 5

125 1 10

number of phonati ons in success i ve

meas uri ng ser ies

34 89 46 45 45 60 87 49 28 30 41 95 21 19 29 57 43 25 49 47 43 73 78 51 65 25 39 34 30 27 38 24 48 38 23 46 30 34 46 35 50 19 82

Table 4- lB. Subject protocols for the 2 1 normal female subje cts , with

respect to age , number of measuring s eries , average speaking voice pitch

level ( fmean

) , and number of phonations in the successive measuring

series . The total number of measuring series was 29 , comprising a total

of 829 ins tances of phonation at various pitches and intensities .

Subject No .

5 9

10 1 1 15 19 22 26 27 28 29 30 32 40 41 49 50 5 1 52 54 56

age years

26 24 19 19 24 17 22 20 29 2 1 2 5 22 25 32 25 25 27 21 20 21 rg

number of series

1 2 2

1 1

2 2 2

2 1 1

2 2

1

f mean Hz

200 220 220 210 220 220 220 195 220 220 220 220 220 200 220 200 200 200 200 220 195

number of phonati ons i n s ucces s i ve

meas ur ing seri es

22 27 26 17 16 30 38 37 43 18 2 1 2 4 36 46 39 32 36 28 17 1 1 18 37 3 2 19 2 5 44 23 27 30

6 1

4.3 Reproducibility of

phonations of a normal

subject

The useful nes s of reference va l ues as a cri ter ion depends on the reproduc ib i l i ty of the experi ­mental res u l ts . A certai n vari at ion i s of course unavo i dab l e .

The number of su i tab l e phonat i ons in a measuri ng seri es is important , as the uncerta i nty gets l ess i f more poi nts determi ne the path of the regress i on l i ne .

F i rs t , the reproduci b i l i ty was determi ned for a great number of phonat i ons { about 100) wi th i dent­i cal target i n tens i ty and target fundamenta l frequency . For th i s purpose , four measuri ng seri es were performed in th ree normal Subjects ( Nos . 2 , 8, and 24) , see 4 . 3 . 1 .

The accuracy wi th wh i ch a certa i n regres s i on l i ne fi ts the exper i­mental data i s i ndi cated by the Estima ted Standard Dev i a t i on of Error ( e . s . d . e . ) . On the bas i s of these val ues , we consi dered a further reducti on of data .

I t appea red to be a permi ssabl e approxi mation to des cribe al l resul ts by th ree regre s s i on l i nes . Th i s matter wi l l be di s cus sed further in 4 . 3 . 2 .

Compari sons were made o f these

62

th ree regress ion l i nes per meas­uring seri es for one subject at di fferent times . These series were carri ed out wi th twenty norma l s ubjects at di fferent t i me i nter­val s , rang i ng from 1 day to about 4 years {between the fi rst and the seventh measuri ng series w i th Subject No . 2 ) . Thi s shows wi t h i n wh i ch l i mi ts i n one s ubj ect the regress i on l i ne l i es , if the measurements have been repeated under pos s i bly equ i va l ent c i rcum­s tances . Th i s i s of course of great importance in the assessment o f the effect o f medi cal treatment . The resu l ts wi l l be d i scussed i n 4 . 3 . 3 .

4 . 3 . 1 Reproduc i b i l i ty of phonati ons wi th i n one measuri ng seri es in one ( s i ng l e ) subject

The reproduc ib i l i ty and the degree of variati ons in the aero­dynami c data were i nvesti gated i n a number of sepa rate experiment s . We as ked the subject to t ry to make every phonatory adj ustment al i ke to enabl e us to determi ne the degree of i nvol untary or phys i o­l og i cal devi at ion . Because for each phonat i on the subj ect i ns p i red at l east once , the l a ry nx had to be adj usted aga i n every t ime for

Table 4- 2 . Results of tests of the reproducibility of measurements of

phonations during one measuring series from one single person . The in­

tens ity measurement was made with an accuracy o f � 0 . 5 dB . The coeffi­

cient of variation was defined as the standard deviation divided by the

mean , expressed as a percentage . Between the two measuring series of

Subj ect No . 2 , there elapsed a period of seven month s .

Subject No .

2 2 8

24

freq . Hz

1 25 165 1 10 165

i ntens . number dB of

74 - 76 77 - 81 74 - 77 74 - 78

phonati ons

79 1 08 102 1 14

mean

the requi red pi tch and i ntens i ty . Thi s di d not happen a lways i n exactly the same way , a s mi ght be expected . For our purpose , it was i mportant to know how accurately the subject was ab l e to reproduce the same l aryngeal adj us tmen t .

Four measuri ng seri es were per­formed , wi th three s ubjects i n­s tr ucted exp l i c i tly to repeat exactly the requi red l a ryngeal adj u s tmen t . The pi tch rema i ned the same and in every phonat i on the req ui red i n tens i ty �1as adj us ted by the subj ect as preci sely as pos s i b l e . Phonation took p lace at a p i tch and i n tens i ty experienced by the subject as comfortabl e . The

coeffi c i ent of vari at ion in % fl ow pres s .

1 7 1 2 1 7 1 7

1 6

10 14 14 16

14

subgl . power

24 22 1 7 26

22

effi e .

28 25 2 1 29

26

subjects were i nformed of the purpose of these measurements and i ntentiona l l y tried to keep the vari at ions as l i tt le as poss i b l e . Per measuri ng series we obta i ned about 100 phonati ons . The data for fl ow , pressure , subg l ott i c powe r , a n d effi c i ency were a veraged per meas uri ng seri es , and the standard devi a tion was determ i ned . From th i s , coeffi c i ents of variation were ca l cu l a ted . These ca l cu l a t i ons have been made wi th non-trans formed va l ues . The resul t i s represented i n Tab l e 4-2 .

From th i s tab l e i t appears tha t the var iati on coeffi c i ents for fl ow and subgl ott i c pressure average

63

respecti vely 16% and 14% . The val ue for the var i a ti on coeffi c i ent of the effi c i ency i s remarkably h i gh . We expected thou gh that at a h i gher press ure val ue a l ower fl ow val ue wou l d be observed and v i ce versa . I n the computi ng of the product of pressure and f low va l ues the vari at ion coeffi c i ent for effi ­c i ency woul d then be l ower as a res ul t of a compensati ng acti on . Only i n Subject No . 8 d i d th i s appear more o r l ess to b e the case . I n the two series from Subject No . 2 and in the seri es from Subject No . 24 , there was no com­pensat ing act ion .

The vari ati on coeffi c i ent for the effi c i ency a verages 26% . Sta rt i ng from the var i a ti on coeffi ­c i ents of the va l ues for fl ow and pressure , an expected vari at ion coeffi c i ent can be ca l cu l a ted by addi t i on of the squares of the var i a ti on coeffi c i ents , in the assumption that fl ow and press ure are i ndependent of eac h other . The computed vari at ion coeffi c i ent amounts to 2 1% . Thi s is l ower than the vari at ions present in the measured effi c i ency val ues . There­fore may at l east be concl uded that the rec i procal compensat ing act ion of fl ow and press ure i s �ot very strong .

The estab l i shed vari a t i on coeffi -

64

c i ents are rather great , though we asked the subject to phonate as much as pos s i b l e i n the same way . The dev iat ion of the exper i­mental data i s partly ca used by di ffi cul t i es i n ma i nta i n i ng the sound i ntens i ty at the requi red l evel . For every measuri ng series a certa i n i ntended va l ue for the sound i ntens i ty has been sel ected . Duri ng phonation the i ntens i ty va l ues va ried a round the i ntended va l ue . These variations coul d not be a voi ded . At the el aboration of the curves the i ntens i ty val ues were rounded off and c l a s s i fi ed i n i nterva l s of 1 dB . Th i s seems to be reasonably accurate , but i t means a vari ation o f 26% . Thi s di spers i on of course a l s o has an i nfl uence on the val ues for fl ow, pressure , and effi c i ency .

The observed i ndependence of fl ow and pressure , occu rr i ng a t l east i n three out of four mea s uri ng seri es , is of s i gni fi cance for the theory of voice product i o n . A h i gh subgl ott i c press ure i s obv i ous ly not accompani ed by a l ow a ir fl ow rate i n every l a rynx . Th i s al so means that a phonat i on w i th a h i gh a i r fl ow rate i s not necessari l y accompan i ed by a l ow subg lott i c pressure .

· -1 1 0Hz • - 1 65Hz o-220Hz o-330Hz o-440Hz I

. .� �oc v �

c � • • · �

� � • � ..

'Z:· ce

e.s.d.e.= 0.14

- . "So �

1 .0

q (l/s) 0.5

0.2

0.1

0.05

1 0

p (kPa) 5

� � �

2

c:o_:; . -� �· v

60 70 80

=

0.5

e.s.d.e.= 0.2

90

0.1q 100 °·1

HdB)

e.s.d.e.= 0.20

...... 17 � �� .o

::i WQ:] >..- � • �Y · . "=}. l/ �

/."" •:!l •

.

60 70 80

.

90 100 ! (dB)

1 000

E( 10 1)

1 00

1 0

1

0.1

Figure 4- 1 . Depiction of the experimental data and regression lines for

flow , pressure , and efficiency from the second measuring series from

Subject No. 1 7 . The experimental data from 78 instances of phonation at

five various pitches have been represented . The values for the residual

spread, i . e . the es timated standard deviation of error , e . s . d . e . , have

been mentioned in the figure . It is clear that the experimental data at

the various pitches can hardly be distinguished from each other .

4 . 3 . 2 Regres s i on l i ne for phonat ions i n one measuri ng seri es from one s i ng l e s ubject

The observed d i spers i on of the experi mental data at the same ad­justment of the l a rynx ( 4 . 3 . 1 ) i s a l so present i n phonati ons a t other pi tches and i ntens i t i es .

I n one measuri ng seri es , data for severa l l a ryngeal adj ustments

for pi tch and i ntens i ty a re obta i ned .

Va l ues measu red at va ri ous pi tches appeared to l i e near each other , if they were brought to­gether i n one graph , see Fi gure 4 - 1 . Therefore the ques tion ari ses whether i t wou l d be mea n i ngful to s tudy these measuri ng res ul ts sepa rately .

The d i s pers i on of the experi -

6 5

•-220Hz -•-330Hz t:! • ·-� ..:-440Hz � -660Hz

�-• ..

e.s.d.e.= 0.24

·o !, . � � I;!P • • •

._/o • f/1 • • e.s.d.e.=

0.13 60 70 80 90 100

I ( dB)

1 .0

q(l/s) 0 5

0.2

0.1

0.05

1 0 p (kPa)

5

0.5

0.2

0.1 60 70

.

.

.

. • .4 • · V •/o d1J

u

0 .

e.s.d.e.= 0.27

· � l(

1

1

1

1

000

E( 10'5)

00

0

BO 90 100 °·1

l (dB)

Figure 4- 2 . Depiction of the experimental data and regression lines for

flow , pressure , and efficiency from Subj ect No _ 1 1 . Regression lines

for the complete measuring series have been represented . A fairly high

value has been found for the e _ s _ d . e . for flow and efficiency , see text .

menta l data i s pa rtly due to the fact that not every phonat i on has been produced i n the mos t eff i c i ent way ( see a l s o 4 . 4 . 4 and 4 . 6 ) . The subject was l eft free in th i s respect .

The acceptabi l i ty of worki ng wi th only one regress i on l i ne for the enti re mea s uri ng ser i es , regardl ess of the vary i ng pi tches , was s tudied . Accordi ngly , we made use of the fact that the smal l er the e . s . d . e . i s , the better the re­g res s i on l i ne fi ts the experimental data .

66

The data from the measuri ng seri es of al l normal s ubj ects have been recorded in Tabl e 4-3 (Appendi x ) .

I t i s o f course impos s i b l e to trace the i nfl uences on the e . s . d . e . i n a l l subjects . We had to restri c t oursel ves to g i ve some exampl es and analyse cases with a h i gh and l ow va l ue for the e . s . d . e .

The d i spers i on o f the exper i ­mental data around the regress i on l i ne va r ies cons i derabl y .

I t di verges for the fl ow from

·-220Hz •-330Hz -:-440Hz

. · . . � v = �

c • r

·� � p .

60 70 80

•

--

e.s.d.e.= 0.26

e.s.d.e.=

1.0 q(l/s)

0.5

0.2

0.1

0.05

10 p (kPa)

5

0.5

0.2 0.14

1 100 °·1 90 I( dB)

v· /

• - v-/-/ • '

60 70 80

e.s.d.e.=

90

0.35

100 [ (dB)

1 000

E(.10'')

1 00

1 0

1

0

Figure 4- 3 . Depiction of the experimental data and regression l ines for

flow , pressure , and efficiency from Subj ect No . 3 2 . Regression lines for

the complete measuring series have been represented . A high value has

been found for the e . s . d . e . for the efficiency , see text .

0 .06 ( S ubject No . 50 ) to 0 . 27 ( Subjec t No . 1 2 ) , a vera g i ng 0 . 1 3 .

For the press ure the e . s . d . e . var i es from 0 . 06 { Subj ects Nos . 8 and 50 ) to 0 . 23 ( Subject No . 6 2 ) , averagi ng 0 . 12 .

For the effi c i ency , the e . s . d . e . d i ve rges from 0 . 07 { Subject No . 50 ) to 0 . 35 ( S ubject No. 32 ) , avera g i ng 0 . 18 .

I n Subject No . 3 2 ( e . s . d . e . =

0 . 26 ) and i n Subject No . 1 1 ( e . s . d . e . = 0 . 24 ) , grea t d i s per­s i ons in the fl ow da ta were meas ­ured . The experimental data and

the regress i on l i nes of both sub­jects a re represented i n F i gure 4-2 and F i gure 4-3 respecti vel y , where the frequenci es at which the experimenta l data have been de­termi ned are i nd i cated .

I n Subject No . 11 i t i s obvi ous tha t the fl ow va l ues measured a t 220 Hz l i e rather far from the regres s i on l i ne , and the measured va l ues fo1· the f l ow at 330 Hz nearly a l l l i e under the regres s i on l i n e . For the effi c i ency , the ex­perimental data at 220 Hz and 330 Hz nearly a l l l i e above the

67

regres s i on l i ne . Th i s i s partly caused by the fact tha t the 330 Hz phonat i ons were produced at a l ower subgl otti c pres sure tha n the other phonati ons at a comparabl e i nten­s i ty va l ue . A pos s i b l e expl ana tion for th i s may b e that a t 330 H z a resonance effect of the total vocal tract , together wi th mou thpi ece , fl u i d­recep tac l e , and fl owhead has pl ayed a ro l e . The requ i red i n tens i ty va l ues might then be ach i eved at a l ower s ubgl otti c press ure. House ( 1959 ) and I s s h i k i ( 1964) poi nted out th i s pos s i b i l i ty for certa i n pi tches . However , i n other s ubjects a sys temat i c preference for va l ues around 330 Hz cou l d not be ob­served . Another pos s i b i l i ty may be that at a l ower frequency a more effi ­ci ent vo i ce production resu l ts . However , i n Subj ect No . 32 ( Fi gure 4-3 ) , i t appeared that the pho­nations at 440 Hz were more effi ci en t .

In the F igures 4 - 2 a n d 4-3 , the data have been recorded for the h i ghest va l ues wh i ch have been cal cu l ated for the e . s . d . e . I n these cases the res i dual spread seems to depend on the di fference in pi tch . It was not po�s i b l e , though , to determi ne any rel ati on-

68

sh i p in th i s respect . I n cases i n whi ch the e . s . d . e .

val ues approximated the a verage va l ue , as i n Fi gure 4- 1 , the ex­perimental data at vari ous pi tches l i e c l ose to each other . ( See i n F i gure 4-2 and Fi gure 4-3 the d i s ­pers ion around the regress i on l i ne for pres sure . )

I n cases of a very smal l res i dual spread ( i n S ubject No . 50 , e . s . d . e . = 0 . 06 ) , a s reproduced i n F i gure 4-4 , further analys i s of the re­l a t i on to pi tch has of course hard ly any s i gn i fi cance .

From da ta of tra i ned voi ces o f S i ngers { Nos . 3 , 1 3 , 17 , 6 2 , and 63 ) it appeared , that the res i dual spread in such cases is not much di fferent from the a vera ge val ue , and the s pread of the experimental data around the regress i o n l i ne of the effi ci ency is not noti ceably better than in other subjects ( see Tab l e 4-3 Appendi x ) . In Subj ect No . 62 only i s the res i dual s pread o f the fl ow val ues notably l ower than that of the press ure val ues .

We concl ude that the pi tch has l i ttl e i nfl uence on the course of the regres s i on l i nes . Therefore it i s pos s i b l e to characteri ze the vo ice product i on per mea s u r i ng series suffi c i ently by us i ng one regress i on l i ne only for fl ow ,

T ·-1 65Hz � . 220Hz --330Hz

60

• • .

-. co T

e.s.d.e.= 0.06

..

. 5t A' � � V'

70 80

e.s.d.e.=

90

0.06 100

! (dB)

1 .0 q{Jfs)

0.5

0.2

0.1

0.05

1 0 p (kPa)

5

0.5

0.2

0.1

.v.: _,I-7

t

60 70 80

e.s.d.e.=

l

90

0.07

100 ! (dB)

1

1

000

Euo·•>

00

1 0

1

0

Figure 4-4 . Depiction of the experimental data and regression lines for

flow , pressure , and efficiency from Subject No . 50 . The regression lines

for the first complete measuring series have been represented . For flow ,

pressure , and efficiency , low values have been found for the e . s . d . e .

Differentiation o f the experimental data according to pitch hardly has

any significance .

pressure , and effi c i ency , res pecti ve ly .

4 . 3 . 3 Regress i on l i nes o f measuri ng series from one s ubject at di fferent t imes

I n 12 ma l e Subjects { Nos . 1 , 2 , 3 , 8 , 12 , 1 3 , 16 , 17 , 18 , 35 , 6 1 , and 62 ) and 8 femal e Subjects { Nos . 9 , 10 , 26 , 2 7 , 28 , 30 , 49 , and 50) more than one seri es was carri ed

out . In two ma l e Subjects ( Nos . 1 and 62 ) measuri ng seri es were taken three times and i n one ma l e Subj ect ( No . 2 ) seven times .

For every measuri ng seri es the val ues for fl ow , press ure , and effi c i ency ha ve been ca l cu l a ted at the same i ntens i ty i . e . at the a verage of the mi drange i ntens i ty val ues { l

m ) of the sepa rate meas ­uring seri es . I n th i s way the be­havi our of the same l a rynx at vari ous days was al ways compared

69

0 100

E ( 10 ' )

10 0 -� ;_::::?' � f-

/ //

1.0 q (l/s)

0.5

0.2

0 1

account a l s o , i t may be ass erted that there i s a good rep roduc­i bi l i ty .

Th i s ca n be i l l ustra te d wi th the a i d of the experimental data from

� #" l#'" o.o5 Subject No . 2 , who has been exam­

i ned s even times ( Fi gure 4 - 5 ) and

0 D 1 0 two more Subjects , No . 10 ( Fi gure

A� 1 � w �

� � /' �

5 P <kPal 4-6 ) and No . 6 1 ( Fi gu re 4-7 ) . These three s ubjects had no vocal t ra i n­i ng . Between the two meas uri ng series of Subj ect No . 6 1 one month and i n the case of Subj ect No . 1 0 , 0 .5

0. 1 60 70

Figure 4-5 .

80 90 100 ! (dB)

0 .2

0

Depiction of the regression lines

for seven measuring series from

the male Subject without voice

training , No . 2 . Between the first

and the last measuring series ,

about four years elapsed . It i s

obvious that the differences are

small , especially those for the

subglottic pressure . The flow

values sho1" greater differences .

at the same i ntens i ty val ue . I t appea red that i n mos t cases

the d i ffe rences i n the course of the regres s i on l i nes of di fferent measuri ng seri es of the same s ub­ject were smal l . I f , moreover , the di s pers i o n of the i ndi v idua l data i s ta ken i nto

70

i ndeed , 22 months el apsed . I t natura l ly i s not fea s i b l e to

represent graph ica l ly a l l the re­sul ts w ith respect to the repro­ducibi l i ty . The data are gi ven i n Tabl e 4-4 (Appendi x ) .

4 . 3 . 3 . 1 D iscuss ion o n the res ul ts

In eva l uati ng the resu l ts when more than two meas uri ng series were obtai ned from the same s ub­ject , we have used the di fferences bet1·1een t110 successi ve meas u ri ng seri es .

Ail' flow pate

The greatest d i fference for the fl ow is 135 ml / s , determi ned be­tween the two meas uri ng ser ies i n Subject No . 1 2 . The remai n i ng d i f-

0 100

(,10'')

10 0

0

1

----

/L V/ �

a __.!---_ ::::::---b

V/ // lij'

b// v-·

/'

/ » r:-----

b

0.1 60 70 80 90

Figure 4-6 .

100 ! (dB)

1.0 q (l/s)

0.5

0.2

0.1

0.05

0.01

1 0 p (kPa)

5

0 .5

0 .2

0

Depiction of the regression lines

for both measuring series from the

male Subject without voice train­

ing , No . 10 . Two years elapsed

between the two serie s . The dif-

ference i n slopes of the regression

lines for pressure are nearly the

highest slope differences es tab­

lished in the measurements of re-

producibility . I n the first meas­

uring series , the value for the

slope of the flow regression line

is small and for pressure large ,

whereas in the second measuring

series , the reverse is the case .

Therefore , the regression li nes

for efficiency run paralle l .

0 100

E(.10'' )

10 0

0

------------

/ /

� I--� a v f

-9/ 7• � v

�� b 1

/_...-�

0. 1 60

Figure 4- 7 .

70 80 90 100 ! (dB)

1.0 q(lts)

0.5

0.2

0 1

0.05

O.DI

1 0 p (kPa)

5

0.5

0.2

0.1

Depiction of the regression lines

for the two measuring series from

the male Subj ect without voice

training , No . 6 1 . One month elapsed

between the two measuring series .

A good reproducibility exists be­

tween the measuring series .

ferences a re much sma l l er and al l l i e be l ow 90 ml /s , averagi ng 32 . 5 m l / s .

Natural ly , the val ues for the s l ope of the regress i on l i ne a l so sho�1 vari a ti ons . The di fference i n the va l ue of the regres s i on coeffi ci ent b i s i n one case only more than 0 . 0 1 ( S ubject No . 26 ) . The average di fference amounts to 0 . 005 .

7 1

Subglottic pressure

I n 17 out of 27 assessed combi ­nati ons the di fference between pressures appeared to be sma l l er or equal to twi ce the error of meas uri ng ( i . e . 0 . 1 kPa , 1 cmH20 } . The greatest dev i at ion has been obse rved i n Subject No . 13 , 0 . 34 kPa ( 3 . 4 cmH20 ) . Th i s fair ly l a rge di fference may pos s i bl y be the consequence of the fact that in the fi rs t meas uri ng seri es from th i s s i nger only h i gh sound i nten­s i ti es were used .

The s l ope o f the regress i on l i nes a l s o appea rs to di ffer l i ttl e . The absol ute devi ati ons in the data , as represented for the regre s s i on coeffi c ient b i n Tab l e 4-4 , a re nowhere l a rger than 0 . 0 1 . What a di fference of about 0 . 01 i n b ac­tua l l y s i gni f ies can be read from Fi gure 4-6 , S ubject No . 10 , i n wh i ch the regress i on l i nes for pres sure have a di fference for the s l opes of 0 . 009 .

On an avera ge , the di fferences i n the val ues for b are much l ower ,

Efficiency

For the effi c i ency i t ho l ds tha t , due t o the s teep course of the regres s i on l i ne , a sma l l change of the s l ope may l ead to a rather cons i derabl e di fference in the val ues at Im .

The variati ons of the effi c i ency val ues were greater than those o f the fl ow and pres s ure . The average di fference amounted to 1 . 9 x 10-5 , the l a rgest di fference was found in Subject No . 28, 8 . 7 x 10- 5 •

As far as di fferences i n the s l opes are concerned , i n th i s respec t , some h i gh val ues were observed ( i n the S ubjects Nos . 1 , 28 , and 49 respecti vely val ues of 0 . 0 1 5 , 0 . 0 2 , and 0 . 016 } . The aver­age di fference though is ha rd ly any grea ter than the one observed for fl ow and pressure, v i z 0 .006 .

The di fferences i n the val ues of Erel ( see Chapter 3) e xpressed in dec i bel appear to vary between 0 and 3 .4 dB . Thi s l as t val ue has been observed in Subject No . 1 2 .

about 0 .003 . Thi s di fference i s 4 . 3 . 3 . 2 S i gn i f i cance of E rel for the compari son of regress ion l i nes

present i n F i gure 4-7 (Subject No . 6 1 ) , as the di fference of the s l opes of the regres s i on l i nes for the effi c i ency .

72

W i th the re l ati ve effi c i ency meas ure Erel ' expres sed i n decibel , i t i s pos s i b l e to i nd i ca te the

effi c i ency of vo i ce production in each s i ng l e case ( see 3 . 6 ) .

The va l ue Erel i s subject to i nci denta l va ri ati ons . The degree i n wh i ch th i s occurs i n meas uri ng series at di fferent times from the same subject determi nes wh i ch change of Erel i n patients i s s i gni f icant .

The var iance of the i nc i dental vari ati ons of Erel i n normal s ub ­jects who have been exami ned more than once , see Tab l e 4-3 , has been estimated from poo l ed va ri ances of these subjects .

E ( ni - 1 ) 2 ci

X s i E ( ni - 1) ( 4- 1 )

n i number of observati ons i n the i -s t person

S i standa rd devi at ion i n the i -s t person

Herewi th has been assumed that the vari ances for a l l persons are i denti ca l .

of Erel , i s thus estima ted a s

8� = 2 x ei 1 . 30 ; (8v = 1 . 14 ) .

By assumi ng that the d i fference between two measuri ng seri es i s normal ly d i s tr ibuted w ith zero expectancy and a s tanda rd devi a t i on ov ' es timated at Bv = 1 . 14 ( a t 2 7 degrees o f freedom) , the i nterva l of �Erel wi th the chance probabi l i ty range , i s

(-t 0. X OV ; t 0. X (jv) \ 1-2 1 -2

1-o. , the

( 4-2 )

Here , t1_7 i s the 1� s t fract i o n

o f the t-di s tri bution wi th 27 de­grees of freedom . For 1-o. = 0 . 10 , we fi nd t0 .9 5 = 1 . 70 3 : the i nterval is ( - 1 . 94 ; 1 . 9 4 ) .

Th i s means that i t may be con­s i dered a s i gn i fi cant change be­tween mea suri ng seri es w i th an unrel i ab i l i ty threshol d of 10� i f the di fference /�Erel l is l arger than 2 dB .

Ca l cu l at ion y iel ds 2 a = 0 . 65 (a = o . 8 1 ) . 4 . 3 . 4 Summary , i ntra - i nd i v i d ual

and i nter- i nd i v i dual di fferences

In compari ng the measuri ng series in pati ents the di fferences i n Erel , 6Erel are made use of . The var iance of the di fference of two i ndependent quanti ties , i n our case ' Erel ' equal s the sum of the i r va ri ances .

The vari ance of the di fference between two measuri ng seri es , i . e .

The di fferences between the re-gres s i on l i nes of the measuri ng seri es of one s i ngl e subject at various times appear in genera l not to be great .

I t i s obvi ous that these di ffe-

73

rences wi l l be much smal l er than those occurri ng between vari ous s ubjects . Compare e . g . i n Tab l e 4-3 the di fferences between fl ow data from Subj ect No . 12 ( about 300 m l /s } , Subj ect No . 30 ( about 75 ml / s } , or Subject No . 49 (about 1 15 ml /s } .

The di fferences i n press ure and effi c i ency a l s o appea r to be greater between the i ns tances of phonation of vari ous i nd i v i dua l s than those measured i n one s i ng l e s ubj ect. Thi s accentuated the good reproduc i b i l i ty of the measure­ments .

The good reproducib i l i ty i s a l so i l l us trated e . g . by the remarkably l ow fl ow val ues from Subject No . 30 . I n a second measu r i ng series after fi ve months , p ract i ­cal ly the same experi menta l data were obtai ned . These l ow fl ow val ues consequently go a long wi th a rema rkably h i gh effi c i ency , �1h i ch was the same for both measuri ng seri es ( see Tab l e 4-3 } .

I n Subject No . 27 , i n the fi rst measuri ng series a rema rkabl e course of the regres s ion l i ne for fl 01� was observed . Contrary tu a lmost a l l other measuri ng seri es , the fl ow decreases at i ncreas i ng sound i n tens i ty ( s ee the negati ve va l ues for the regress i on coeffi ­ci ent b i n Tab l e 4-3 } . Moreover ,

74

i t wi l l be noti ced that the pressure ri ses only very gradua l l y (b devi ates only very l i ttl e from zero ) at i ncreas i ng i ntens i ty . At the second measur ing seri es , a fter 2 months , p racti cal l y i denti cal res u l ts �1ere obta i ned . Thi s fact , too , s peaks i n favour of a good reproduc i b i l i ty .

Sei dner , Wend ler , and StUrzebecher ( 1975 ) reported ex­tens i ve ly on the great i nter- i nd i ­vi dual s pread i n the data from severa l normal s ubjects , mak i n g the determi nati on o f normal val ues very di ffi cul t . The d i spers i o n of fl ow data at accurately defi ned pi tches and i ntens i t i es appea red to be 2 to 3 t imes smal l er in a s i ngl e subject than bet1�een s ub­j ects (Sei dner and StUrzebecher , 1978} .

The di s pers i on described by Sei dner et a l . - expres sed i n the variation coeff ic ients - corre­sponds wi th the val ues descri bed in 4 . 3 . 1 .

For al l ma l e s ubjects the repro­ducib i l i ty of the effi ci ency appears to be very good . I n fema l e subj ects the variati ons a re some­what l a rger i n genera l . Th i s i s mai nly the resu l t o f di fferences i n fl o1� val ues . The sma l l est var iations were observed i n the pressure val ues .

4.4

4 . 4 . 1

The set of all regression

lines of the normal

subjects: reference areas

I ntroducti on

The regress i on l i nes of the seri es from a l l normal s ubjects form th ree bund l es of l i nes : f low , pres sure , and effi c i ency . Due to thei r di vergent courses , these bundl es each cover a certa i n terri tory cal l ed i ts reference area . Some of these l i nes wi l l be d i s cussed separately , because they form the l im i ts of the reference area . The es tab l i shed reference area s wi l l be di s cussed i n 4 . 4 . 3 .

I n 4 . 2 has been menti oned a l ready that a fa i rly l a rge number of the meas ured phonations were rejected by trai ned l i s teners . Regress i on l i nes based upon these rejected phonati ons are compared wi th the reference areas i n 4 . 4 . 4 .

The regress i on l i nes from the ma l e and femal e s ubjects have been represented together , as they cover nearly i denti cal areas in both men and women . Moreover , there i s no s i gn ifi cant di fference if on ly the regress i on l i ne from the fi rs t measuri ng seri es or those from a l l seri es are used . Thi s coul d be expected , because the i ntra- i nd i ­v i dual vari ation i s sma l l er than the i nter- i nd i vi dual vari at ion .

The regress i on l i nes for a i r fl ow rate , subgl otti c pressure as we l l as for effi c i ency occupy a l arge area . Th i s shows how l a rge the i nter- i ndi vi dual d i fferences are . Regres s i on l i nes at the borders of the bund l es have been g i ven a subject- number, to i nd i cate thei r ori g i n . These regres s i on l i nes wi l l be d i s cus sed sepa rate ly .

A i1• flow rate

4 . 4 . 2 The regress ion l i nes for the fl ow

The set of a l l regres s i o n di verge very much : e . g . a t 7 0 dB l i nes

I f the regres s i on l i nes from vari ous subjects are represented together , mak i n g mutua l compari son pos s i b l e , there appea r to exi st cons i derab l e di fferences . Fi gure 4-8 provi des a c l ea r p i cture of these di vergi ng va l ues .

the fl ow vari es from l ess than 50 ml/s to about 300 ml /s . The l ower border of the reference area i s formed by both regrE _ s i on l i nes from Subject No. 30 . Low fl ow va l ues a l so have been measured i n Subj ect No . 28. The regress i on l i nes i n these s ubjects l i e ma i n ly be l ow 100 ml / s .

7 5

The range of the a i r fl ow rate data at a moderate i nten s i ty i s i n general 100 m l/s to 300 ml / s , b ut l a rger di fferences occur at t he ul t imate val ues of the i nten­s i ty ranges .

I n some normal s ubjects the rel a ti on between fl ow and i n tens i ty i s very wea k , wh i ch a l so appea rs from the fact that the regres s i on coeffi c i ent b i n Tabl e 4-3 i s a l most zero .

The h i ghest va l ue for b has been determi ned in Subject No. 44 ; th i s regre s s i on l i ne l i es at the upper l i mi t of the bundl e at 80 dB . Up to an i n tens i ty of 75 dB the re­g ress i on l i nes from the S ubj ects Nos . 5 and 12 form the upper l imi t . Above 9 5 d B the l i mi ts are deter­m i ned by the regress i on l i nes from the Subjects Nos . 3 , 18 , 19 , 2 7 , and 5 3 .

Subglottic pressure

The regre s s i on l i nes for the press ure appear to occupy a sma l l e r area than those for the fl ow . The i nter- i ndi vi dual di fferences are sma l l er .

The i ntra- i nd i v i dual di fferences are a l s o sma l l er than those for the fl ow .

The i ncrease i n subg l otti c press ure connected wi th an i ncrease

76

in sound i ntens i ty appea red to be practi ca l ly the same in most of the s ubjects ( vi rtual equal va l ues of the regress i on coeffi c i ent b ) .

One of the regress ion l i nes of Subj ect No . 27 shows a course wh i ch devi ates from the other l i nes ; i t takes a nearly hori zonta l l evel . Because of the great dynami c range th i s regress i on l i ne run s at the upper border at l ow sound i nten­s i ti es and at the l ower border a t h i gh sound i ntens i ti es .

The l ower l i mi t of the bundl e of l i nes i s determi ned furthermore by the regress i on l i ne from Subject No . 1 2 . The fl ow regres s i on l i ne of one of the measuri ng series of the same person l i es at t he upper border of the bundl e of l i nes . However , both l i nes are not deri ved from the same measuri ng seri es . The border l i ne wi th l ow s ubgl ott i c pres sure val ues , i nd i cated as 1 2b , i s not accompan i ed by a regress i on l i ne with h i gh fl ow va l ues . The fl ow regress ion l i ne correspondi ng wi th 12b l i es in the mi dd l e of the b undl e of l i nes for fl ow . The h i gh regress i on fl ow l i ne 12a though is accompa nied by rather l ow pressure va l ues , see Fi gure 4-8 .

A t h i gh sound i ntens i t i es ( above about 90 dB ) very h i gh subg l ott i c pres sures i n s i ngers ( tenors ) we re meas ured . The regress i on l i nes s how

Figure 4-8. The set of all regression lines from the phonations with non­

deviant sound quality. The regression lines from 72 measuring series in

45 normal subjects have been represented. The numbers indicate the sub­

jects , the indices a , b , and c designate different measuring series in

the same subject.

va l ues wh i ch surpass a val ue we l l above 5 kPa ( 50 cmH2o ) . Such h i gh val ues practi ca l ly only occur i n the s i ngers i n our i nvesti gat ion . I n a l l remai ni ng subjects , i n­c l udi ng those who a l so coul d pro­duce a sound i ntens i ty of 105 d B , the subgl otti c press ure remai ns l es s than about 3 . 5 kPa ( 3 5 cmH20 ) . Both Tenors ( Nos . 1 3 and 62 ) wi l l be di s cussed i n Chapter 6 .

Efficiency

The spread of the regress i on l i nes for the effi c i ency i s sma l l er than the spread i n the a i r fl ow rate , but l arger than that of the subgl ott i c pres sure . Th i s coul d be the resu l t of a compensati ng effect ( h i gh va l ues for flow at l ow s ubgl ott ic press ures and v i ce versa ) . Th i s effect had been pre­v ious ly observed in Subject No . 8 ( see 4 . 3 . 1 ) . I n Subject No . 12a , the h i gh val ues for flow coi ncide

77

wi th l ow va l ues for subgl otti c press u re . Th i s means that the effi c i ency regress i on l i ne runs through the centre of the reference area . Such a compensat ing effect , though cou l d only occas i ona l ly be observe d .

The l ow fl ow va l ues from Subject No . 30 resu l t in a h i gh effi ci ency . The effi ci ency regres s i o n l i nes ( together wi th those from Subject No . 28) defi ne the upper border of the bund l e of l i nes for effi ­ci ency , wh i l e the regres s i on l i nes for press u re on the other hand l i e i n the mi ddl e of thei r bund l e .

A t the l ower s i de run the effi ­c i ency regress i o n l i nes from S ubjects Nos . 5 and 44 ; the h i gh fl ow va l ues i n these cases have not been compensated by l ow press ure val ues .

Above 85 dB , by a fa vourab l e combi nati on of fl ow a nd pressure val ues the regress i on l i ne from Subject No . 49 i s s i tuated at the upper s i de of the bund l e .

The steep s l ope o f the effi c iency regres s i o n l i nes from Subject No . 27 i s the res ul t of the hori zontal course of the regress i on l i ne for pres s u re and the decrease of the fl ow at i ncreas i ng i ntens i ty . By th i s comb i nati on , th i s Subject de l im i ts the effi ci ency bund l e

78

at the i ntens i ty top s i de , i . e . above 9 0 dB .

At h i gh i ntens i t i es , the re­gres s i on l i nes from the s i ngers appea r to l i e i n the l ower pa rt of the bund l e of l i nes .

4 . 4 . 3 Reference areas for flow, subgl otti c pres sure , a nd effi c i ency

From the broadness of the bundl es of regress i on l i nes , i t i s obvi ous that i t is not pos s i b l e to provi de preci se ly ci rcumscri bed "normal va l ues " for fl ow , pressure , or effi c i ency .

The s ubjects i n our experiments , as opposed to the pati ents ob­served , never had vocal d i s turb­ances , the i r l a rynxes showed no abnormal i t i es , and the produced sounds were not aud ib ly dev iant . Thei r regres s i on l i nes thus show whi ch variati ons may occur i n "norma l " phonat ions of subj ects . The l a rge s pread of the regress i o n l i nes from the norma l subjects , i nterferes wi th a n assessment of abnorma l i ty of a regress i on l i ne from a pati ent .

Rej"erence areas

The reference areas for fl ow , press ure , and effi c i ency have been

I( dB)

Figure 4-9 . Delimi tation of the reference areas . Contour lines around

the regression lines indicate the limits of the reference areas .

determi ned by drawi ng contour l i nes around the respecti ve bund l e of l i ne s . These contour l i nes have been drawn i n s uch a way tha t a l l regress i on l i nes are enc i rc l ed , see Fi gu re 4-9 .

4 . 4 . 4 Rejected phonati ons i n rel at ion to the reference areas

I n 4 . 2 has been menti oned that a fa i rl y l a rge number of phonat ions from norma l s ubjects have been rejected by experi enced l i s teners . Th i s amounts to 1531 from a tota l

of 4267 i nstances of phonati o n . The rejected phonations were

ma i n ly produced at p i tches and/o r sound i n tens i ti es at the l imi ts of the voca l potenti a l i t i es . The perti nent phonati on then l i es at the border of the phonetogram (see 2 . 2 . 1 . 2 ) . Moreove r , for certa i n subjects the pre-sel ected fre­quenci es were ei ther too l ow or too h i g h . For these subjects , i t was st i l l pos s i b l e to phonate fo l ­l owi ng the g i ven pi tch , but the qua l i ty of the voi ce was not sat i s­factory and soft phona tions often appeared to be breathy .

79

At pi tches i n the ne i ghbou rhood of the reg i s ter trans i t ion from ches t voi ce to fa l setto vo i ce , a number of mai n ly soft phonations have been as sessed as dev iant and were rejected .

F i na l l y , a phonat i on occas i onal ly seems to have a devi ant sound qua l i ty whereas the succes s i ve phonation , fol l owi ng th i s one and s ung at the s ame p i tch and i nten­s i ty , seems a l together normal i n sound qual i ty . Th i s i s due , of cours e , to t he poss i bi l i ti es of vary i n g the sound qual i ty . A de­viant phonation ens ues when the attenti on of the subject s l a ckens . Occas i onal ly a remi nder resu l ts i n a favourabl e effect , but g i vi ng i ns tructi ons on the qual i ty of the vo i ce ought to be avoi ded as much as pos s i b l e . Sometimes a cri ti ca l remark l eads to confus i on .

We s tudi ed the course of the regres s i on l i nes of 21 d i s carded meas uri ng series wi th res pect to the reference areas , see Fi gu re 4- 10 .

The 2 1 regress ion l i nes compri sed 817 phonati ons . The othe r rejected phona tions ( 7 14 ) ori g i nated from the 45 norma l s ubjects i n Tab l e 4- 1 . I f these 7 1 4 phona tions are i nc l uded i n the ca l cul at ion of the re l evant regres s i on l i nes , i t

80

appears that the course of these l i nes is only very l i ttl e i nfl uenced .

Air flow rate

I t appears that only two fl ow regress ion l i nes of di sca rded seri es run outs i de the reference area , the remai ni ng ones a l l l i e wi th i n the fl ow reference area . Mos t of these d i s carded regress i on l i nes , though l i e i n the upper part of the reference area . T h i s actua l l y means however , that hoarse or breathy phonati ons a re poss i b l e wi th the s ame a i r fl ow rates a s norma l sound i ng phonati ons .

Two other di s carded fl ow re­gres s i on l i nes runn i ng approx i ­mately through the m i dd l e of the fl ow reference area , ori g i nate from the same s ubject. These phona tions were rega rded by the l i steners as strai ned .

Suhg lottic pressuJ'e

The pressure regress i on l i nes of the dev i ant phonations l i e i n the upper part or j ust outs i de the press u re reference area .

Two of the pressure regress i on l i nes , whi ch go on to 100 dB res p . 105 dB , ori gi nate from the same person . Th i s i s the same subj ect

.-----,-----,---.---,---,--.--.-.-.----, 1000

f---+--4---l---+--+--! E(.10"5)

70 80 90 100 °1 ! (dB)

Figure 4- 10 . Depiction of the regression lines from re jected measuring

series . The relevant phonations have been rejected as a result of the

judgement of listeners who found the vocal sound to be deviant . The

majori ty of the regression lines lies within the reference areas . From

an aerodynamic point of view , the deviant phonations are distinguished

from phonations with non-deviant sound qua lity to a minor degree only .

menti oned a l ready , whose phonati ons have been j udged as strai ned . I t i s remarkab l e that above 9 0 dB hi s pres s ure regress i on l i ne goes up to val ues wh i ch are otherwise on ly observed i n t�10 S i ngers ( Nos . 13 and 62 ) .

F:j'ficienuy

As cou l d be expected mo$ t effi ­ci ency regres s i on l i nes for the d i scarded phonations l i e i n the

l o�1er part of the effi c i ency ref­erence area , and some j ust outs ide it . So most of the d i scarded pho­nati ons are l ess effi c i ent than those that were accepted . Due to the combi na tion of pressure and fl ow the effi ci ency regres s i on l i nes dev iate the most .

I n summa ry , i t may be stated that the i nfl uence on the reference areas of eventual devi ati ng pho­nati ons wh i ch escaped reject i on

81

i s not grea t . Th i s i s of course re l ated to the i nter- i ndi vi dual di fferences . The aerodynami c data of a devi ant phonati on from one person may thus l i e c l ose to the data of a good phonation from an­other person .

Th i s means a l so that a dev iant va l ue may s ti l l l i e wi thi n the reference area , even though it i s cons i derably di fferent from the normal val ues of the same s ubject .

4.5 Published data concerning

'normal values' compared

with data determined in

this investigation

We found i n the l i terature only three i nves ti gations of s imul ­taneous measurements of a i r fl ow rate , s ubg l ott i c pressure , i nten­s i ty , and p i tch . I n pub l i shed resul ts of other i nvesti gations the great degree of i nter- i nd i ­vi dual va ri at ion does not become apparent because s imu l taneous measurements were ca rri ed out i n these on only rel ati vel y few sub­jects . Mos t studies compri s i ng measurements on a great number of subjects report the mean a i r fl ow rate only .

Compa ri son of our data wi th data from the l i terature i s , moreover , di ffi cul t , because i n ma ny cases

82

nei ther i ntens i ty nor pi tch have been reported . I n many publ i cati ons too , only mean val ues and, i n s ome cases , a meas u re of vari at ion have been mentioned .

I n order to eval uate experimen tal data from a pati ent , the range of the experi mental data from normal subjects i s of greater i m­portance than the mean val ues . Ko i ke and H i rano ( 1968) s tress t h i s fact emphati cal ly and they handl e the stati sti cal concept " c ri t i ca l regi on" .

4 . 5 . 1

4 . 5 . 1 . 1

Data for the a i r fl ow rate

Range Jnd mean val ue

For fl ow measurements various methods were used . Tab l e 4-5 gi ves a su rvey of i nvesti gations based on at l east ten subjects reporti n g a i r fl o�1 rates compared wi th our own study . A subdi v i s i on i s made for each of the di fferent methods .

The measuri ng procedures are d i v i ded by us i n seven subgroups accord i ng to the method for estab­l i shi ng the a i r fl ow ra te : - -

! . By d i v i d i ng the V i tal Capaci ty ( VC ) , beforehand obtai ned wi th

a spi rometer , by the maxi mum pho­nati on time of a max i ma l ly sus­ta i ned phonation ( the Phonation

Quoti ent , PQ) , as i n the studies by H i rano , Koi ke , and von Leden ( 1968) , Basti a n , Sasama , and Unger ( 19 78 ) , and Sawash ima , Yoshi oka , Honda et a l . ( 1978) .

I I . By deri vation from the vol ume curve , obtai ned w i th ei ther

a spi rometer (mfr) or a bag , as in the studi es by Roudet ( 1900a ) , Gutzma nn and Loewy ( 1920 ) , Schi l l i ng ( 1925 ) , Dehne ( 1944 ) , van den Berg ( 19 56 ) , Kunze ( 1962) , Ptacek and Sander ( 1963a , b ) , and Sa1�as h i ma , Yos h i oka , Honda et a l . ( 1978) , or �1i th a bodypl ethysmo­graph , as i n the s tudi es by Bouhuys , Procto r , and Mead ( 1966 ) .

I I I . By di vi di ng the total vol ume curve of expi red a i r duri ng

phonat i on , obtai ned wi th a spi ro­mete r , by the maximum phonati on time after maxi mum i ns pi ration (MFR ) , as i n the studies by I s sh i k i , Okamura , and Morimoto ( 196 7 ) , and Sa�1ash ima , Yosh ioka , Honda et a 1 . ( 1978) .

I V . By di vi di ng the to ta l vol ume curve , obta i ned by i nte­

grat ion of the pneumotachograph si gnal duri ng max ima l ly sustai ned phonat i on , after maxi mum i nsp i ­ra tion ( the Phonation Vol ume) , by the phonati on time , as i n the stud i es by I s s h i k i ( 1964 , 1965 ) , Yanagi hara , Koi ke , and von Leden ( 1966 ) , I ss h i k i , Okamura , and

Morimoto ( 1967 ) , Yanagihara and Koi ke ( 1967) , Yanag ihara and von Leden ( 1967 ) , H i rano , Ko i ke , and von Leden ( 1968 ) , Ko i ke a nd H i rano ( 1968) , Iwata and von Leden ( 1970a , b ) , Iwata , von Leden , and W i l l i ams ( 19 72 ) , Kel man , Gordon , S impson et a l . ( 1975 } , Basti an , Sasama , and Unger ( 1978) , Gordon ( 1978) , Gordon , Morton , and S impson ( 1978 ) , and H i ppel and Mrowi nski ( 1978) .

V . By d i v i d i n g the vol ume cu rve , obta i ned by i ntegrat ion of

the pneumotachograph s i gna l , by the phonation time, as i n the s tud ies by I s s h i k i ( 1964 ) , I ss h i k i a n d von Leden ( 1964 ) , a n d von Leden ( 1968) .

V I . By di rect readi ng from the pneumotachogra ph curve ,

averagi ng over an i n terval of some seconds (2-5 s } , as i n the s tudies by I ssh i k i and von Leden ( 1964 } , Vaughn ( 1965 ) , I s sh i k i , Okamura , and Morimoto ( 1967 ) , McG l one and Sh i pp ( 197 1 ) , Sh i pp and McG l one ( 19 7 1 ) , StUrzebecher , Sei dner, �Jagner, et a l . ( 1973 ) , Sei dner, Wend l er , and StUrzebecher ( 1975 ) , and Sei dner and StUrzebecher ( 1978) .

V I I . By di rect readi ng from the pneumotachograph curve , as

i n the s tudi es by Luch s i nger ( 195 1 } , Vogel sanger ( 1954) , Cavagna and Marga ri a ( 1965 , 1968 ) , Rubi n ,

83

Table 4- 5 . A survey of data from the literature concerning the range ,

the average value , and the dispersion of the experimental data for flow

in sustained phonations together with the number of investigated subj ects

( males and female s ) . The conditions of the experiments are given in the

last column . The Roman numbers indicate the measuring procedure , see text.

name of fi rs t author

I . H i rano

Sawas hima

Bastian

! ! . Kunze Sawash ima

I I I . I ss h i k i

Sawash ima

number of testpers .

( 1968 ) 1 25 m 25 f

( 1 978) 25 m 25 f

( 1978) 5 1 f

( 1 962 ) ( 1978)

10 m 25 m 25 f

( 1967 ) 5 m 5 f

10 m+f ( 1 978) 25 m

25 f

I V . Ya na9i hara ( 1 966) 1 1 m 1 1 f

Yanagi hara ( 1967 ) 1 1 m 1 1 f 1 1 m 1 1 f 1 1 m 1 1 f

range ml /s

69 - 3072 78 - 241 2 5 6 - 205 2 23 - 2302

73 - 284 3 66 - 162 38 - 140

94 . 7- 153 68 . 7 - 162 68 . 7 - 162 45 - 14 7 1 3 - 181

55 - 310 55 - 310

mean ml /s

145 137 130 126

S . D . condi t ions

comf . p i tch and i nt .

34 . 6 comf . p i tch a nd i nt . 47 . 9

200 100 sel . i nt . and comf . piUJ

160 1 1 2 89

20 23 . 0 23 . 7

sel . p i tch and i nt . comf . p i tch

1 23 . 1 19 . 5 1 33 . 0 33 . 0 127 . 9 27 . 0

comf . p i tch and i nt .

9 6 23 . 7 comf . p i tch and i n t . 97 39 . 1

1 1 2 100 1 53 149 1 18 100 1 14 95

30 . 4 comf . p i tch and i nt . 2 2 . 8 56 . 2 h igh p i tch 37 . 8 30 . 4 med i um p i tch 22 . 8 39 . 5 l ow p i tch 37 . 4 a l l with comf. i nt .

I s sh i k i ( 1967 ) 5 m 104 . 7- 164 . 3 1 26 . 2 21 . 1 comf . p i tch and i n t .

84

5 f 69 . 0- 171 . 0 135 . 9 36 . 4 1 0 m+f 69 . 0- 1 7 1 . 0 131 . 1 30 . 5

tab l e 4-5

name of fi rst author

cant . I V H i rano

Ko i ke

Iwata Ke l man

Hi ppe 1 Ba st ian

V . I s s h i k i

Vaughn

number of tes tpers .

( 1968 ) 25 m 25 f

( 1968) 2 1 m 2 1 f

range ml /s

46 - 2222 43 - 1972

( 1972 ) see H i rano ( 1968 ) ( 19 7 5 ) 28 m+f 80 - 200 3

( 1978) ( 1978 )

( 1964 )

( 1965 )

19 m+f 5 1 f

- m f

36 m+f 20 m

190 - 300 3

62 360 44 - 3 15 76 - 182

1 75 - 2503

mean ml /s

101 92

S . D . condi tions

comf . p i tch a nd i nt .

1 1 2 .4 36 . 2 4 comf . p i tc h , med i um 9 3 . 7 3 1 . 6 4 l oudness

1 5 1

141 1 19 1 30

62

22 . 5 2 5 . 0 26 . 0

comf . pi tch a n d i nt . + h i ghest a n d l owest p i tch in chest regi ster comf . pi tch , 3 se l . i nt . se l . pi tch and comf. p i tch

extremes i n p i tc h and i nt . i nc l uded comf . p i tch and i nt . 4 s e 1 . p i tc hes , i nt . range 6 dB

I s s h i k i ( 1967 ) 5 m not di fferent from the 5 f val ues g i ven i n group I I I

V I . Sh i pp ( 1971 ) 14 m

Sei dner ( 1975 ) 37 m 237 - 4B2 63 f 195 - 44 1

V I I . Luchs i nger ( 195 1 ) 20 m+f Vogel sanger ( 1954 ) 1 29 m+f

Schutte thi s ' 24 m monograph 2 1 f

45 m+f

4 1 - 2 16 40 300

105 - 350 45 - 300 45 - 350

transformed values were used for calculation

2 calculated critical region 9 5 %

1 7 7 3 30 . 4 3 at 25% i nt . l evel va rious p i tches 2 pi tches

181 132 160

i nt . range 10 dB

various p i tches various pi tches , fl ow range determ i ned at 70 dB ( see F i gure 4- 1 1 ) vari ous pi tches fl ow range determi ned at 70 dB ( see Fi gure 4-9 )

85

not explicitly given , derived from published figures or tables

the difference between the flow rate values at 70 dB for the

trans formed mean �. and for transformed (� + sl in ml/sec .

LeCover , and Vennard ( 1967 ) , Ca vagna and Campores i ( 19 74 ) , Schutte and van den Berg ( 19 76 ) , and th i s monograph .

Luchs i nger ( 19 5 1 ) was the fi rst to use a pneumotachograph for measuri ng fl ow i n phonat i on . He exami ned 20 s i ngers .

At the s ame sound i ntens i ty , f l ow va l ues between 4 1 ml /s and 216 ml /s were meas ured for va ri ous pi tches . Such di vergent val ues were ex­p l a i ned by hi m as consequences of i nter- i ndi vi dual di fferences i n the structure of the l arynx .

Voge l s anger ( 1954) regi stered the fl ow i n 2g s i ngers for two i n tens i t i es at vari ous pi tches . I n h i s pub l i cat ion , the data for fl ow together wi th the data for i ntens i ty have been pres ented for 960 phonations . Though exact compari son of the sound i ntens i ti es i s not pos s i b l e ( d i fference i n the d i stance to the mi crophone etc . ) , the experimental da ta per s ubject were converted by us to regress i on l i nes . These regress i on l i nes are represented in Fi gure 4- 1 1 . They cover prac­t i ca l ly the same area as the re­ference a1·ea de termi ned by us for fl ow .

Kunze ( 1962) concl uded that the rel ation bet1·1een fl ow and i ntens i ty

86

shows rather l arge i nter- i nd i vi dua l di fferences .

I s sh i k i and von Leden ( 1964 ) i ntroduced the i dea of a l l ow i ng the s ubj ects to phonate at a com­fortabl e pi tch and i ntens i ty of thei r O\'ln cho i ce .

I n a l l i nvesti gations fol l owi ng thei r pri nci p l e of "easy and com­fortabl e phonation " , the fl ow ranges appear to be sma l l er than those imp l ied by our reference area ( Fi gure 4-9 ) .

I s sh i k i and von Leden ( 1964 ) g i ve for the a i r fl ow rate at "easy phonation" a range of 76 ml /s to 182 ml /s . If the phonations w i th "extreme vari a ti ons i n p i tch and i ntens i ty" are i ncl uded , the ranges are 62 m l/s to 360 ml /s for ma l es and 44 m l/s to 315 m l/s for fe­ma l es . The i ntens i ty ranges were not menti oned . The l imits g i ven by these authors for the extremes of p i tch and i ntens i ty do not di ffer much from the l imi ts of our reference area .

H i rano , Ko i ke , and von Leden ( 1968) , Koi ke and H i rano ( 1968) , and Iwata , von Leden , and W i l l i ams ( 1972 ) use the stati st ica l concept of "cri t ica l regi on" for the des ­cri pti on of norma l val ue l i mi ts . For th i s purpose they sta rt from the mean va l ues for ma l es a nd fe­ma l es and arri ve at di fferent

l i mi ts for mal es and fema l es . H i rano , Koi ke , and von Leden ( 1968 ) assert , "The c ri ti ca l region i n­di cates that a mean fl ow rate of less than 46 eel s in a ma l e or 43 eels in a fema l e or a mean fl ow rate greater than 222 eels i n a ma l e or 197 eels i n a femal e s hou l d b e regarded a s abnormal . "

Compared wi th our reference area (F i gure 4-9 ) the pub l i s hed " norma l val ues " are s l i ghtly sma l l er . Th i s may be due to the procedure used by other authors . At a free choi ce of pi tch and i ntens i ty i n most of the reported experi ments the s ub­jects were as ked to phonate after a max ima l i ns p i rati on . In some cases , the l ongest phonati on of a number of phonations has been taken as the " norma l val ue" ( H i rano , Koi ke , and von Leden , 1968 ; H i rano , 1975 ; Sawa sh ima , Yosh i o ka , Honda et a l . , 1978) . Moreover , the s ubjects i n these i nves ti gat ions were g i ven ca refu l i ns tructi ons and often beforehand got an opportuni ty to get fami l i a r �1i th the requi red phona tory tas k . I t may be assumed that the con­s umpt ion of a i r in th i s procedure wou l d be l es s than i n our method .

Sawas h ima , Yos hi oka , Honda et a l . ( 1978) i nves ti gated the i n­fl uence of the phona tory tas k on the fl ow val ue . They concl ude that

100 0.01 l (dB)

Figure 4- 1 1 .

Depiction of the regression lines

for flow values obtained by evalu­

ation ( us ing the method described

in Chapter 3 ) of the data from

Vogelsanger ' s investigation. He

considered 29 subj ects , 25 singers

and 4 patient-singers , Vogelsanger

( 1954 ) . The regression lines mainly

lie within the in 3 . 4 . 3 indicated

reference area. The lines marked

with 4 , 25 , 26 , and 28, are from

the patient-singers , using

Vogelsangers numeration .

measuri ng of the sma l l est fl ow val ues for easy phonation after norma l breath i ng should be pre­ferred i n exam i ni ng and recordi ng the every day use of the vocal apparatus . Moreover , by ta k i ng the sma l l est flow va l ue Sawash ima et a l . obtai ned l ow mean val ues .

Cavagna and Marga ria ( 1965 ) and

87

Cava gna and Campores i ( 1974) ex­p l a i ned the fact that a phonation wi th cons tant p i tch and sound in­tens i ty may have cons i derably di f-

from hi s S i ngers Nos . 18 and 20 , partly l i e under our reference area .

ferent fl ow rates . They estab l i shed 4 . 5 . 1 . 2 Reference regress i o n 1 i ne that a certa i n mi nimal fl ow was

needed to keep the phona tion go i ng . The amount o f the mi n ima l fl ow i s rel ated to the sound i ntens i ty . W ith h i gh speed mot ion-pi ctures of the voca l fo l ds duri ng phonat ion they found that fl ow va l ues h i gher than the mi n imal fl ow val ues may be obta i ned by l etti ng a i r pass vi a the pos teri or part of the g l otti s ( "a i r shunti ng" ) . Th i s part wi l l then obvious ly be brought i nto i ncompl ete adducti on . The v ibration of the voca l fol ds i s often l imi ted to the anteri or part of the g l otti s .

The m i n imal fl ow has a l so been di scussed by Luchs i nger ( 195 1 ) , who defi ned the concept "Mi n ima l l uft " , coi ned by the s i ngi ng-teacher Paul B runs , as " das mog l i chst k l e i ne Luftquantum mi t dem e i n gut brauchbarer Ton i n jeder Stimml a ge und i n jeder Ton­hHhe erzeugt werden kann " .

Voge l sanger ( 1954) a l so ass umed that profess i onal s i ngers use l ess a ir than untra i ned peopl e . I n v i ew of h i s own data , however , ( see F i gure 4- 1 1 ) , thi s i s not the cas e , only two o f the regress i on l i nes ,

88

Al l authors stress the fact that the mean fl ow val ue i n women l i es bel ow that va l ue i n men . To be abl e to compare these mean va l ues wi th our val ues we computed reference regress i on l i nes . These were de­termi ned from the average va l ues of the regres s i on coeffi c i ents b and a .

Tab l e 4-6 gi ves the data for the a i r fl ow rates . The reference re­gres s i on l i nes were computed for ma l es and femal es sepa rately and for both groups together .

A number of subj ects had been exami ned more than once , a re­ference regress ion l i ne a l so was computed then for thei r first measuri ng seri es a nd for a l l measuring seri es together .

I t appeared that i t makes l i tt l e d i fference whether only the fi rst measuring ser ies of a s ubject or a l l measuri ng seri es together are used .

Tabl e 4-6 shows that a rema rkab l e di fference between ma l e and fema l e val ues wa s a l s o present i n the mea n va l ues of the fl ow data measured

Table 4-6 . Table of the regression coefficients of the flow reference

regression line for various groups of normal subjects in this investi-

gation . The calculated flow has been recorded for the intensity values

70 dB and 90 dB .

measuring coeffi c i ent of ca l cu l ated fl ow number of series regress ion in ml /s at measuri ng

bx10- 2 a 70 dB 90 dB seri es

ma l es fi rst 1 . 290 1 . 353 180 326 24 a l l 1 . 2 18 1 . 405 181 3 1 7 43

fema l es fi rs t 1 . 085 1 . 386 140 23 1 2 1 a l l 1 . 049 1 . 388 132 2 1 5 29

ma l es + fi rs t 1 . 194 1 . 368 160 278 45 fema l es a l l 1 . 15 1 . 398 160 271 72

by us . Though mos t authors have descr i bed th i s phenomenon , no sati s factory explanation has been g i ven so fa r .

We suggest that the fact that the cons umpti on of a i r in phonation in women i s sma l l er than in men may be connected wi th the fact that the fema l e gl otti s is l ess i n l ength and wi dth . Th i s i s the con­sequence of the sma l l er ana tomi cal structures , wh i ch a l s o causes the h i gher s pea k i ng voi ce p i tch l evel in women .

Our mean fl ow val ues at 70 dB -132 ml / s for women and 181 ml /s for men - are for men some�1hat

h i gher, than the mean val ues found by other authors .

4 . 5 . 2

4 . 5 . 2 . 1

Data for the s ubg l ottic pressure

Range and mean va l ue

I nvesti gati ons on subgl otti c pressure i n phona tion have been performed by van den Berg ( 1956 ) , I s s h i ki ( 1959 ) , Kunze ( 1962 , 1964 ) , Ladefoged ( 1962 ) , and L i eberman ( 1968) . I n these studi es the number of subj ects was smal l , but Loebel l ( 1969 ) des cri bed di rect pressure meas urements i n 100 subjects and 47 patients ; however , he only gave

89

an overa l l s urvey of experimenta l data . 1 )

Van den Berg ( 1956 ) meas ured pressures in one subject ( d i rectly and i ndi rectl y ) vary i ng from 3 . 5 cmH2o to 50 . 5 cmH2o at a dynami c ra nge of about 40 dB .

Issh i k i ( 1959 ) and Perk i ns and Yanagi hara ( 1968) regi s tered the s ubg lottic press ure by di rect measu rement , respecti vely in one and i n two s ubjects , at va ri ous p i tches and i ntens i t i es . Thei r da ta corres pond wi th those of van den Berg .

Kunze ( 1962 ) , i n ten ma l e s ub­jects , usi ng a di rect method ( puncture of the trachea ) , found subg lott i c va l ues duri ng phona t i on rang ing from 2 . 75 cmH2o to 24 . 84 cmH20 .

For every pi tch and i ntens i ty , Kunze took the average of three measurements . He measured a t fi ve pi tches , di vi ded proporti ona l l y over the i ndi vi dual vo i ce frequency ra nge . At every p i tch the va l ues of the s ubgl ott ic press ure for fi ve

1 ) Very recently we received from

Prof. Dr . E. Loebell the disser­

tations of Nold { 1 967 ) , Glatz

{ 1 9 7 0 ) and Schuck ( 19 7 1 ) on direct

vocal i ntens i t i es were determ i ned . Sh ipp and McGl one ( 197 1 ) reported

val ues of press ure and f l ow i n 14 s ubjects for two sound i ntens i t i es ( 25% and 75% of the i ntens i ty ranges ) at vari ous pi tches . For every pi tch they gave a mean val ue for the subgl otti c pressure . These mean val ues ran ge from 4 . B9 cmH2o ( S . D . 0 . 5 ) to 1 2 . 77 cmH20 ( S . D . = 1 . 02 ) .

As can be seen from Figure 4-9 , we found s ubgl ottic press ure va l ues varyi ng from 0 . 15 kPa ( 1 . 5 crnH20 ) to 10 kPa ( 100 crnH20 ) .

At moderate va l ues of i ntens i ty , the subgl otti c press ure vari ed over a range of about three times the l owes t val ue , due to the i nter­ind i vi dual vari at i on s .

A t a n i ntensi ty l evel o f 7 0 dB , the s ubgl otti c pressure va ried from 0 . 2 to 0 . 7 5 kPa ( 2 to 7 . 5 cmH20 ) , at 90 dB from 0 . 75 to 3 kPa ( 7 . 5 to 30 cmH2D ) .

Subg l otti c pressure val ues above 3 . 5 kPa ( 35 cmH20 ) were found ma i nly in tra i ned tenor s i ngers .

4 . 5 . 2 . 2 Reference regress i o n l i ne

subglottic pressure measurements in From the mean val ues of the re-patients , and of Mendl ( 1970 ) on gress i on coeffi c i ents of the sep-normal subj ects . arate regress i on l i nes , a reference

90

Table 4- 7 . Table of the regress ion coefficients of the pressure reference

regression line for various groups of normal subj ects in this investi-

gation . The calculated pressure has been recorded for the intensity

values 70 dB and 90 dB .

measuri ng coeffi c i ent of ca l cul ated press . number of series regress i o n i n k P a a t measuri ng

bx10-2 a 70 dB 90 dB series

ma l es f i rs t 2 . 644 - 2 . 220 0 . 43 1 . 45 24 a l l 2 . 622 - 2 . 198 0 . 43 1 . 4 5 43

fema l es fi rst 2 . 333 - 1 . 97 5 0 . 45 1 . 32 21 a l l 2 . 323 - 1 . 980 0 . 44 1 . 29 29

males + fi rst 2 . 496 - 2 . 105 0 . 44 1 . 39 45 fema l es a l l 2 . 50 -2 . 1 10 0 . 44 1 . 38 72

regres s i on l i ne is ca l cu l ated , the regress i on coeffi c i ents for va ri ous groups of subj ects be i ng gi ven i n Tab l e 4- 7 .

I t i s obvi ous from the cal c u l ated mea n subgl otti c press u re val ues for 70 dB and 90 dB that practi ­cal ly no di fferences were found between the va ri ous groups .

Al l authors agree that s ubg l otti c pres sure duri ng phonation i s c l osely re l ated to sound i ntens i ty .

For the subgl ott ic pres sure range , Loebel l ( 1969 ) and other authors have reported pressures up to about 3 . 5 kPa ( 35 cmH20 ) i n normal subjects .

Apart from certa i n excepti ons ,

e . g . the tenor s i ngers , our upper l imi t a l so appears to l i e at about 3 . 5 kPa { 35 cmH2o ) .

4 . 5 . 3 Data for the effi c i ency

4 . 5 . 3 . 1 Range and mean va l ue

I n determi ni ng vocal effi c i ency i t i s necessary to kno�1 the a i r fl ow rate a s wel l a s the subgl otti c pres sure of the same phonat ion . Therefore , the publ i shed data con­cern i ng th i s subject are l i mi ted .

Van den Berg ( 1956 ) ca l cul ated effi ci ency val ues for the phonat ion of the vowe l /a/ at a dynami c range of about 40 dB , varyi ng from

9 1

Table 4- 8 . Table of the regression coefficients of the efficiency

reference regression line for various groups of normal subj ects in this

inves tigation . The calculated efficiency has been recorded for intensity

values 70 dB and 90 dB .

mea s uri ng coeffi c i ent of ca l cu l ated effi e . number of series regress i on i n

bx10-2 a 70 dB

-5 x10 at 90 dB

meas uri ng s e r i es

ma l es f irst 6 . 066 - 3 . 974 1 . 9 30 . 5 24 a l l 6 . 1 59 -4 . 048 1 . 8 3 1 . 3 43

fema l es f irst 6 . 587 -4 . 252 2 . 3 47 . 5 2 1 al l 6 . 628 -4 . 248 2 . 5 5 1 . 1 29

ma l es + fi rs t 6 . 309 -4 . 104 2 . 1 37 . 5 4 5 fema l es a l l 6 . 348 - 4 . 1 28 2 . 1 38 . 4 7 2

5 - 5 0 . 45 x 10- t o 4 5 x 1 0 , dependi ng on the sound i n tens i ty , the pi tch , and the openi ng of the mouth .

Ma rgar ia and Cavagna ( 1959 ) and Cavagna and Ma rgaria ( 1965 , 1968) di scus sed the i ncrease of effi ­ci ency at i ncreas i ng sound i ntens i ty .

I s sh i ki ( 1964 ) obtai ned va l ues -5 - 5 o f 3 x 10 to 140 x 10 , u s i ng

a s i ng l e s ubjec t . Perki ns a n d Yanagi hara ( 1968)

a l so i nves ti gated a si ng l e s ubj ect . The effi c i ency val ues , as deri ved from the i r fi gures by us , vari ed from about 5 x 10- 5 to 65 x 10-5 . These va l ues fa l l wi th i n i n the reference area determi ned by u s .

92

Moser and Ki ttel ( 1979 ) recently pub l i s hed resu l ts of i nves ti gati ons on effi c i ency i n voi ce producti on . They determi ned a i r fl ow rate and subgl otti c press ure wi th the a i d of a bodypl ethysmograph i c method , and ca l cu l ated the effi c i ency by a di rectly coupl ed computer . Thei r resul ts correspond with van den Berg ' s data .

As can be seen from F i gure 4-9 , we found effi c i ency va l ues vary i ng from 0 . 1 2 x 10-5 to 400 x 10- 5 for a sound i ntens i ty ra nge of 47 dB .

At a g i ven i ntens i ty va l ue , the effi c i ency vari ed wi th i n a range of about 10 dB , due to the i nter-

r / -.- / 7 / -----" [!--1--\ ----� �

I ./

1'--...

�7 ___./

1 .0 q(lls)

O S

0.2 0.1 0.05

y 1 0 / v p�

p (kPa) 5

v./ v./ ----�../"' ./_...../ v

c v / "P_j 100 ° 10 eo 90

0.5 02

60 ! (dB)

,-

7 /v /

/ 17 / / /

v v/v / 1/ 1/ I I

..i..._

/ l--/ 1000 E ( 10 '>

/. 7 E�1 00 7 17 1 0

1

1---'--.L 70 eo 90 100 °1

! (dB)

Figure 4- 1 2 . Depiction of the reference areas and reference regression

lines for flow , pressure , and efficiency, ascertained on the basis of

the 2 7 36 non-deviant phonations , measured in this investigation in 72

measuring series in 45 normal subj ects .

i ndi v i dual vari ati ons . At an i n tens i ty l evel of 70 dB ,

the effi c i ency vari ed from 1 x 10-5

to 10 x 10- 5 , at 90 dB from 10 X 10- 5 tO 1 10 X 10- 5 .

4 . 5 . 3 . 2 Reference re gres s i on l i ne

Mean va l ues for the effi c i ency at 70 dB and 90 dB were ca l cu l a ted from the reference regress i on l i nes for vari ous groups , see Tab l e 4-8.

As expected the mean effi c i ency i n women appea rs to be h i gher than in men . The di fference between vari ous groups of normal subjects aga i n proved to be very sma l l .

The reference regress i o n l i nes based on a l l 72 measuring series i n 45 normal subjects are repre­sented , together wi th the reference areas , i n F i gure 4-12 .

93

4.6 Normal and deviant

sounding phonations from

the same subject: intra·

individual comparison

I n previ ous secti ons the great i nter- i ndi vi dual d i fferences have been d i scussed , i t was observed that the aerodynam i c data of a dev iant sound i n g phonat i on from one person may l i e very c l ose to those of a norma l sound i ng pho­nati on from another s ubject .

We sha l l now cons i der whether i ntra- i nd i vi dual d i fferences be­tween normal and dev i ant sound i ng phonati ons can be asses sed . For th i s purpose we may compa re the experi mental data of i ntenti ona l ly hoarsely produced phonati ons w i th the regress i on l i nes and data from the same s ubj ect .

Certai n normal s ubj ects were asked duri n g a meas uri ng ser ies to produce hoarse phonat i ons . The curves from the hoarse phonati ons were el aborated in the u s ua l way . S i nce the number of hoa rs e pho­nations was smal l , no computi ng of regress i on l i nes fol l owed .

The aerodynami c di fferences be­tween hoa rse and 11 normal 1 1 pho­nati ons w i l l be i l l ustrated by a few exampl es .

94

Subject No . 2 .

S ubject No . 2 was a s ked , after a us ual measur i ng seri es , to phonate i n a very breathy manner (at E 3 , 165 Hz , about 75 dB ) .

The experi mental data are i n­d i cated i n F i gure 4- 13 .

Thi s fi gure a l so shows the re­gres s ion l i nes of t_he seven meas­ur ing series w i th 344 non-deviant phonati ons .

The flow data from the fou r hoa rse phonati ons can b e d i s t i n­gui shed c l early des p i te the d i s ­pers i on of the experi mental data around the regress ion l i nes . The fl ow data l i e by a fa ctor of about 3 above the other data at the same i ntens i ty . The pres s ure data from the hoa rse phonati ons , however , are found i n the same a rea a s those from the normal phonati ons . The effi c i enci es of the hoarse phonati ons l i e l ower by a factor of about 3 .

O n the ba s i s of Fi gure 4 - 13 , the s i gni fi cati on of phonation at phonetogram extremes , especi a l ly wi th regard to the fl ow data , can be i l l u stra ted. I n the d i s cus s i on of the rejected dev iant phonat i ons , we rema rked ( 4 . 4 . 4 ) that these phonat i ons often appeared to be I

/ F::::.. 1.0

./ . . · - · . q (l/s) __ -k,.._...--7 . . : . ' . . . . s

( · • • j .:·.

/ __..--/ 0.2 1�p .· . ' · ' ·

0.1 \ ---�---­�-+t=.__...------*"::::::...-J---+--+----lo.os

60 70 80

v 10

/ p (kPa)

[7 s

./ ' ' J

90 100 °·1 I( dB)

/. (� 7·: · : F / . . » / v . . �/ v

� r/. fWj . ·.·

'/

� v// [#· "/ 1/

1 000 E(.10'5)

-

>'/.

v 1 00

1 0

1

60 70 80 90 100 ! (dB)

0

Figure 4- 1 3 . A comparison of experimental data from four phonations in­

tentionally produced hoarse sounding and experimental data from a great

number ( 344 ) of phonations with non-deviant sound quality in Subject No .

2 . The experimental data from the hoarse phonations have been marked with

a circle .

produced at the l i mi ts of the voca l poten ti a l i t i es .

I n Subject No . 2 , nearly a l l pho­na ti ons be l ow 75 dB w i th fl ow va l ues above 300 ml /s ori gi nated from phonati ons at A2 ( 1 10 H z ) .

From the phonetogram of th i s Subj ect ( Fi gure 2-4 ) i t may be seen that th i s pi tch l i es at the l i mi t of h i s voca l ra nge and tha t at th i s frequency there i s only a ve ry sma l l dynami c range . At 1 1 0 H z , a max imum sound i ntens i ty of no more than 70 dB cou l d be reached .

Loud phonati ons at ext reme pi tch l evel s l ead eas i l y to a hi gh fl ow va l ue and decrea s i ng effi c i ency . Desp i te these h i gh fl ow va l ues , the phonati ons d i d not g i ve the impress i on of bei ng hoarse , but probably , neverthel ess , l ie i n an area of trans i tion to hoarse pho­nati ons . However , at 1 10 Hz , i n some o f the measuri ng series from Subject No . 2 no f low val ues ex­ceed i ng 300 ml/s were found . Th i s was the case , i ndeed i n about ha l f of the 60 phonati ons at

9 5

v f': � _...., � � J ( 1 � � l--/ \ ----c.--�

/ / v� fq � �/

__..---::::: � ;-v ( � v _,. \[/ 60 70 80 90 100

[ (dB)

1 J) q(l/s)

0.5

0.2

0.1

0.05

1 0 p (kPa)

5

0.5

0.2

0.1

I

/ 000 E ( IO ')

/ �) I � v i 00

/ � / : h v · f 11 / _,} �/

/ lh:. . / /

1/l I 60 70 80 90 100

! (dB)

I

I

0

Figure 4- 1 4 . A comparison of experimental data from four phonations in­

tentionally produced hoarse sounding and experimental data from pho­

nations with non-deviant sound quality from both measuring series in

Subj ect No . 1 7 . The experimental data from the hoarse phonations have

been marked with a circle .

1 10 Hz . I n th ree meas uri ng seri es , the fl ow val ues at 1 10 Hz l i e defi n i tely bel ow 300 ml / s . Appa r­ently the vo i ce production at th i s extreme pi tch l evel i s mo re effi ­c ient some days more than others .

Svb,ject No . 1 7 .

I n Fi gure 4- 14 , the experi menta l data from tv10 meas uri ng seri es i n Subj ect No. 1 7 (Bari tone ) are gi ven . At the end of a seri es , the s ubject was asked to produce a

96

hoarse sound . The data for flow , pressure , and

effi c i ency i n four hoa rse pho­nati ons have been marked i n Fi gure 4- 14 in order to d i s ti ngu i s h them from the data from normal phonat ions .

I t i s obvi ous that the hoarse phona tions were characteri zed by hi gh fl ow val ues , wh i ch d i st i ngu i s h them from norma l sound i n g phonat ions .

The pres sure data appea red not to be conspi c i ously d i fferent from

/ i'--.: ?

( . ------�

1 ----� ___./ \ -----1----�

./ v /.I.--. v /

_......--: � ------17

( 7 v /

/

/

1 .0 q(l/s)

0.5

0.2

0.1

0.05

1 0 p(kPal

5

0.5

0.2

60 70 80 90 100 O.l

! (dB)

/ I 7

1 000 E( 10.1)

f.-

17 1 00

v I// / / 7 r7 / /1// v wv / 1/·

V ; I

60 70 80 90 100 ! (dB)

1

1

0

0

:igure 4- 1 5 . A comparison of experimental data from two phonations in­

tentionally produced hoars e sounding and experimental data from pho­

nations with non-deviant sound quality in Subject No . 60 . The experi­

mental data from the hoarse phonations have been marked with a circle .

those of normal phonati ons . The l ow s ub gl otti c pressure at 80 dB from th i s s ubject compensates for the hi gh fl ow , caus i ng the effi ­c iency to l i e nea r to the re­gress i on l i ne deri ved from norma l phonati ons . The remai n i ng three effi c i ency va l ues l i e beneath those from norma l phonati ons and outs i de the reference area .

Subject No. 60 .

The fl ow data from the hoa rse phona ti ons , represented i n Fi gure

4- 1 5 , l i e evi dently wi thi n the re­ference area . Compared w ith the fl ow va l ues commonly used by th i s subject , the hoarse phonati on fl ow val ues are h i gher by as much as a factor 2 and can be c l early d i s ti ngui shed from the norma l val ues .

The s ubgl ott i c pressures i n the hoa rse phonations were found out­s i de the pressure reference area . Ho�1ever , as the regres s i on l i ne of th i s subj ect l i es at the border of the press ure reference area , the pressures duri ng hoarse pho-

9 7

nati ons can ha rd ly be d ist i ngu i shed from the press ures duri ng normal phonati ons i n th i s s ubject .

The voca l effi ci ency i n hoarse phonat ion is l ower than in norma l phonati on ; these effi c i ency val ues l ie outs i de the reference area .

In summary , we may s tate that i ntentiona l ly produced devi ant phonati ons cannot a l ways be d i s ­tingu i s hed i n an aerodynami c i nter­i ndi vi dua l compari son ( reference areas ) .

However , i n an i ntra- i ndi vi dual compari son of phonation , wi th respect to the s ubject ' s regre s s i on l i ne , the di fference between hoarse and norma l phona ti ons s tands out c l earl y . Th i s l eads to the con­c l us i on that the i n i t i a l per­formance of a pa tient or norma l s ubj ect may be taken as a re­ference s ta ndard for eva l uati ng changes i n aerodynami c behavi our , e . g . as a res u l t of therapeuti c measures .

9 8

Chapter 5 Investigation conducted in patients

5.1 Introduction

I n th i s Chapter that part of the research project conducted w i th voca l pati ents w i l l be d i s cussed .

I n 5 . 2 a s urvey i s g i ven of the s ubject protoco l s of the pati ents , d i v i ded i n three Pati ent Groups .

Fi rs t of a l l , the ques ti on ari ses v1hether the aerodynami c data can be used for d i a gnos ti c pu rposes . To answer th i s ques t i on the resu l ts of the fi rs t meas uri ng seri es are compared i n 5 . 3 and the extent to wh i c h the regres s i o n l i nes for fl ow , press ure , and effi ci ency i n the pati ents l i e i ns i de or outs i de the reference areas of the normal subj ects i s cons i dered .

The res u l ts of a l l measuri ng seri es are g i ven in 5 . 4 , under the subd i vi s i ons of the th ree Patient Groups .

T he effect of a gi ven treatment app l i ed to the pati ents was as­sessed by compari ng the res ul ts of vari ous meas uri ng series i n a s i ng l e pati ent . I n such cases an i ntra- i nd i vi dual compari son wa s made .

The d i s cuss i on of the pati ents w i 1 1 rema i n 1 i m i ted to a few typi ca l cases i n each subgrou p .

5.2 Survey of patients

classified in Groups

The pati ents compri sed 30 men and 37 women , se l ected by the random chances of c l i n i ca l pract i ce .

The maj ori ty o f the pati ents v i s i ted the Ear, Nose and Throat Cl i n i c of the Gron i ngen Uni vers i ty Hospi tal (D i r : Prof . Dr . P . E . Hoeksema ) and the Logoped i c/ Phon i atri c Department because of vo i ce or voi ce production com­pl a i nts . Al l pat i ents had i n common that thei r voi ces sounded more or l ess abnorma l .

The pati ents were gi ven numbers accordi ng to the sequence of the i r exami nati on .

I n three Pat i ents , Nos . 5 , 1 7 , and 22 , l ess than 1 0 phonati ons were measured . These series were put as i de . Therefore , 64 pat i ents ( 29 ma l es and 35 fema l es ) rema i ned , see Tabl e 5-1A and B , provi d i ng a total of 2549 phonati ons at va rious sound i ntens i t i es and p i tches .

I n 1 7 pati ents , fo r va rious reasons , a measurement \"las per­formed on ly once . Three pati ents di ed , tl-10 pati ents under\"lent l a ryngectomy , ten pati ents fa i l ed to respond after repeated ly being cal l ed u p , and t\-10 pati ents proved

99

100

Table 5 - l A . Subject protocols for 29 male patients with respect to age ,

number of measuring series , average speaking voice pitch level ( fmean )

' and number of instances of phonation in each measuring s eries .

Pat i ent age s pea k i ng voice p i tch l evel and number of No . yea rs phonati ons i n s ucces s i ve measuri ng series

fmean ' Hz number of phonati ons 1 st 2nd 3rd 4th 1 st 2 nd 3rd 4th

1 1 4 7 120 125 43 33 1 2 56 195 120 32 42 13 65 125 35 15 81 1 1 5 130 2 7 44 1 6 42 160 2 7 18 70 1 10 1 10 32 1 6 2 1 49 1 10 1 10 53 3 2 23 50 100 100 43 3 1 2 5 70 170 165 44 24 28 68 130 130 56 31 37 180 145 48 5 2 32 65 100 100 58 35 33 42 120 145 135 36 2 2 2 3 34 25 100 1 10 1 10 1 10 28 46 81 65 36 26 195 1 75 53 49 39 73 1 10 1 10 37 27 40 19 160 165 38 49 41 20 140 165 26 26 43 20 150 5 1 48 19 125 1 10 37 47 49 45 100 90 39 59 50 56 120 1 1 5 1 38 9 5 9 5 46 6 1 58 20 120 130 130 76 38 53 6 1 5 7 125 140 50 25 64 24 125 125 46 42 65 48 120 44 66 72 135 16 67 40 125 26

Table 5- l B . Subj ect protocols for 35 female patients with respect to age ,

number of measuring series , average speaking voice pitch level ( f ) , mean

and number of instances of phonation in each measuring series .

Pa tient age speak i ng voi ce p i tch l evel and number of No . years phonations i n s uccess i ve measuri ng series

fmean ' Hz number of phonations 1st 2nd 3rd 4th 1st 2nd 3rd 4th

49 2 10 24 2 54 240 240 25 17 3 42 200 200 3 1 6 1 4 24 200 215 2 10 3 1 4 3 7 2 6 63 230 17 7 16 200 50 8 28 2 10 200 3 5 36 9 44 200 aphon i c 24 2 1

1 0 34 1 7 5 2 10 195 46 37 32 14 48 220 235 26 72 19 29 2 10 210 2 10 44 52 54 20 18 200 235 45 51 24 1 7 200 210 36 40 26 31 200 195 42 3g 27 41 230 230 54 63 29 54 190 195 35 42 30 19 2 10 200 5 1 33 35 22 1 70 26 37 18 270 55 38 19 220 2 10 4 1 36 42 30 180 210 30 46 44 20 190 190 190 42 60 68 45 30 120 1 1 0 39 40 46 2 1 200 220 42 55 47 29 200 220 45 60 52 16 2 20 230 58 30 53 16 220 60 54 20 2 10 190 200 40 59 39 55 18 200 210 52 69 56 46 180 230 55 22 57 6 1 200 32 59 35 2 20 36 101 60 23 225 2 10 50 43 62 22 2 1 5 48 63 48 165 200 24 20

to be i n too poor phys i ca l con­di tion for fu rther i nves ti gati on .

I n the rema i n i ng 47 pati ents ( 2 1 ma l e s and 2 6 fema l es ) , a second mea s ur i ng series was performed , tota l l i ng 1927 phonati ons .

For ei ght pati ents , a th i rd mea suri ng seri es appea red to be justi fi ed ( 422 phonati ons ) , and in Pati ent No . 34 , we recorded fou r seri es .

The pati ents were di v i ded i n to three Pati ents Groups . Many sys tems for the cl a s s i fi cat ion of vocal d i s turbances have been des cri bed in the pa s t . Extens i ve s u rveys of the l i teratu re have been g i ven by Gundermann ( 19 70 ) , and by Wend l e r , Sei dner , Ros e e t a l . ( 1973 ) .

I t appea rs that the c l a s s i fi ­cations based on symptoms and s i gns gradua l l y have been rep l a ced by other c l a s s i fi cati ons more c l osely re l a ted to aeti o l ogy and di s turbed functi on .

Genera l l y , voca l d i s turbances are d i v i ded i nto functi onal and organi c d i sorders .

For cl i n i ca l purposes , functi onal vocal di sturb ances often have been di vi ded in a " too much effort" ( hyperfuncti on ) or a " too l i ttl e effort" ( hypofuncti on) cl asses . In exami n i ng the pati ents , an as­ses sment is made a fter observation

102

of such symptoms a s the type of breath i ng , the use of extra­l aryngea l neck musc les and the musc l es of the face, and the general posture .

The vocal d i sturbances a scri bed to organ i c dev iat ions of the vocal fo l ds have been d i vi ded i n prima ry and secondary c l a s ses . An organi c di s turbance i s cons i dered to be secondary i f an acute or c hroni c vocal mi s use i s s upposed to be the fundamental cause of the a i l ment ( e . g . vocal fol d nodul es ) .

For an extens i ve di scus s i on of thes e cl a s s i fi cat ion , we refer to manua l s on phoni atri cs ( Luch s i nger and Arno l d , 1965 , 1970 ; Greene , 1972 ; B iesa l sk i , 1 9 73 ; Damste , 1973a , b ; Bohme , 1974 ; Boone , 1977 ; Wend l e r and Se i dner , 1977 ; W i l son , 1979 ) .

Our cl a s s i fi cation i s pr imari ly based on l aryngos cop i c findi ngs . When a pati ent has such compl a i nts as hoarseness , breath i nes s , hus k i ­nes s , rough vo i ce , ti redness i n spea k i n g , etc . , i ndi rect l aryngo­scopy i s usua l l y i ndi cated as a fi rst step i n d i a gnose .

When at l a ryngoscop i c exami nation an orga n i c d i s turbance of the l arynx was establ i s hed , we have cl as s i fied the pati ent i n Group I .

Group I I and Group I I I conta i n

pat i ents wi th normal voca l fol ds .

G roup I I compri ses the pati ents �1ho were cl i ni cal l y characteri zed as havi ng functi ona l d i sturbances of the vo i ce . The major ity of these pa ti ents did not show a compl ete g l otti s cl osure , for unknown reasons , though the mobi l i ty o f both pa rts of the l a ry nx proved to be undi s turbed .

I n the l i terature , the expre s s i on " functi onal di s turbance" i s used i f no organi c di s tu rb ance of the l a rynx cou l d be estab l i shed . The orga n i c s ubstratum of the func­ti onal di s turbances , however , as observed at i nd i rect l a ryngos copy is in mos t cases better des i gnated wi th the d i a gnos ti c term : " s l i ght adducti on di s turbance" .

Group I I I compri ses pati ents h a vi ng no rma l voca l fol ds , but w i th

di sturbances : " functi onal vo i ce d i sorders " ;

GROUP I I I . Those havi ng norma l voca l fol ds , but s ufferi ng from severe i nnervati on di sturbances .

Th i s c l ass i fi cat i on i s pragmati c usefu l , al though , of course ac­tua l l y i mperfect because i t i s based o n s i mp l e l a ryngoscop i c cri teria for comp l ex cl asses . Not only the nature of the vocal d i s ­turbance i s qui te vari ed , but a vocal di s turbance may have various causes . I n addi t i o n , a pat ient adapts his voi ce consci ous ly or unconsc i ous ly to the res i dual potenti al i t i es . A voca l d i stu rbance often shows a devel opment depend i n g o n many factors . The appearance of symptoms or si gns may therefore depend on severa l causes .

an impai red mobi l i ty of one or both 5.3 Results of first measuring

series in all patients h al ves of the l arynx due to s e vere d i s turbances of i nnervat i o n .

The c l a s s i fi cati on of our pati ents therefore is as fol l o�1s : - ­

GROUP I . Thos e hav i ng orga n i c di s turbances o f t h e voca l fol ds ;

GROUP I I . Those havi ng norma l vocal fo l ds and , i n · most cases , s l i ght adducti on

The res u l ts of the fi rst meas ­uri ng series di verge cons i de ra b l y , because one pati ent i s s i mply not comparabl e wi th another pati ent in rea l i ty , even i f they suffer from the same affect ion .

Moreove r , the i nter- i nd i v i dual va riati ons observed in the norma l s ubjects a l so pl ay a ro l e i n

103

pat ients , apart from the i nfl uence of the perti nent vocal di s tu rbance .

Fi g ure 5 - 1 g i ve a l l regress i on l i nes be l ongi ng to the fi rst meas­uri ng seri es of 64 pati ents i n 2 549 i ns tances of phonat i o n .

The vari ati ons for fl ow a s we l l as for press u re and effi c i ency are great .

5 . 3 . 1 D i s cuss i on on the aerodynami c data

Aiz• flow rate

The regress i on l i nes for fl ow l i e i n that part of the reference area correspondi ng wi th h i gh a i r fl ow rates , i n most cases above the reference fl ow l i ne . However , by fa r the maj ori ty l i e wi thi n the contours of th i s area . Thi s means that the di agnosti c val ue of the a i r fl ow rate in phonation i s smal l .

Data concerni ng the fl ow i n vocal pati ents from the l i terature cor­respond wi th the va l ues obtai ned by us ( Dohne , 1944 ; I s s h i k i and von Leden , 1964 ; Yanagi ha ra and von Leden , 1967 ; Iwata and von Leden , 1970b ; Yanagi hara , 1970 ; Iwata , von Leden , and Wi l l i ams , 1972 ; Ke l man , Gordon , S i mpson et a l . , 1975 ; Gordon , Morton , and S impson , 1978; H i ppel and

104

Mrowi nski , 1978 ; Sawash ima , Yosh i oka , Honda et a l . , 1978) .

Subglottic pressure

The regress i o n l i nes for the pressure l i e outs i de the reference area in fa r more pat i ents . Al l regress i on l i nes i n pat ients l i e above the reference regress i on l i ne .

As far a s the previ ous l i terature is concerned , the subgl ott i c pressure has been measured only in a few cases , ma i nly i n pati ents wi th l aryngea l para lys i s . Compari son with our data , howeve r , i s imposs i b l e because i n formati on concerni ng sound i ntens i ti es i s l acki n g . These data a re necessary for the i nterpretation of the s ub­gl otti c press ure va l ues .

Efficiency

The di spers i o n of the effi c i ency regress i on l i nes i n the patients is nearly twi ce as l a rge a s i n the normal subjects . I t i s obv i ous that the effi c i ency of vo i ce producti on in pati ents is l ow . I n Fi gure 5- 1 , i t was necessary to extend the sca l e at the l ower s i de by one decade for the very l ow regress i o n l i nes .

The effi ci ency of a n abnormal

l (dB)

Figure 5- l . Depiction of regress ion lines for flow , pressure , and effi­

ciency from the first measuring series Hith 64 patients , together with

the corresponding reference areas . In order to represent the very low

e ffi ciency regression lines , the verti cal s cale was extended at the lmter

side by one decade .

l arynx has been des c ri bed i n the l i terature fo r one case on l y , i . e . a pa t i ent s u fferi ng from an un i ­l atera l l a ryngeal para lys i s ( I s s h i k i and von Leden , 1964 ) . Unfortunatel y , the authors men­t i oned nei ther the pos i tion of the vocal fol ds duri ng phonation nor the sound i n tens i ty . Therefore compari son wi th our da ta i s

impos s i b l e .

Dzjlu:unic potentialities

Al l pati ents appeared to be abl e , though often w i th obv ious ly i n ­c reased effort , t o reach a s ound i ntens i ty of 70 dB to 75 dB , 1�h i ch corresponds wi th the sound i n ten­s i ty used i n ordi nary conversati o n .

105

The computed effi c i ency val ue is a meas ure for the func t i on i ng of the voi c e producti on apparatus from an energet ic po i nt of v i ew . A l ow effi c i ency means , that i n order to reach a certa i n sound i ntens i ty , more energy has to be s uppl i ed to the l arynx . Thi s impl i es that phonat ion wi l l be more ti ri ng a nd may cause com­p l a i nts . Moreover, the l a rynx may then devel op pathol ogi cal organ i c d i s turbances , e . g . oedema o f the vocal fo l ds .

The dynami c ranges i n pati ents are in general sma l l er than those in normal s ubj ects . The pati ents have l ess potenti a l i ti es of spea k i ng l oud or shou t i n g .

Characteristic values

The characteri s t i c va l ues of the measuri ng seri es are recorded compl ete ly for the pat i ents i n Tab l e 5-2 (Append i x ) . I n the di s ­cus s i on of the res ul ts we shal l use reduced tab l es , wh i ch gi ve only the mos t i mportant data .

5 . 3 . 2 Di s tr i buti on o f norma l and devi ant regress i on 1 i nes

l i ne ( i . e . Im ) l i es outs i de the reference area .

I n 20 out of 64 pati ents , no dev i ati on was observed i n the aerodynami c data . Th i s means that in about 30% of the cases none of the regress i on l i nes for f l ow , pressure , or effi c i ency l i es out­s i de the reference area . For some pati ents th i s is not remarkabl e , e . g . Pat i ent No . 2 6 , s uffering from a bi l ateral abducti on para lys i s , wi l l not show dev iant aerodynami c va l ues for voi ce product i on , be­cause nearly normal phonat i on i s pos s i bl e .

O u t of the remai n i ng 4 4 patient s , only i n 1 7 cases , about 40% , d i d the fl ow regress ion l i ne l i e out­s i de the reference a rea .

The pressure regress i on l i ne i s dev i ant i n 38 pati ents , about 85� . I n 36 pat i ents , about 80 , thi s i s the case for the effi c i ency regres s i on l i ne .

Tab l e 5-3 gi ves a c l a s s i ficati on of the regress i on l i nes for the three Groups of pat i ents , together wi th the occurrence of comb i nati ons of devi ant regress i on l i nes .

From Tab l e 5- 3 , i t i s evi dent that the fl ow is never dev i a t i ng a l one by i tsel f . If the fl ow i s dev i ant , the effi ci ency , i n any

A regress i on l i ne has been ca l l ed case , i s a l so devi ant . From t h i s dev iant when t h e midpo i n t of the may b e concl uded that i n the case

1 06

Table S- 3 . Classification of the regression lines from 64 patients , Sub­divided in the three main Patient Groups .

reg ress i on l i nes

devi ant

fl ow press ure effi ci ency fl ow and pressure fl ow and effi ci ency p ressure and effi c i ency fl ow , pressure , and effi ci ency

non-devi ant

total

of a devi ant h i gh fl ow no compen­sa t i on by a l ow subgl o tti c press ure occurred , i n whi ch case the effi ­c i ency mi ght fal l wi thi n the reference area .

Thi s tab l e shows that i n Group I a s wel l as i n Group I I , i n four pa t i ents only the pressure va l ues a re devi a n t . In these ei ght pa t i ents the hi gh s ubgl otti c press ures are compensated by l ow a i r fl ow rates , whi ch makes the eff i c i ency val ues l i e wi thi n the reference area .

Moreover , i t appears even i n Gro up I , tha t pa ti ents hav i n g

number of Patient Group pat i ents I I I I I

44 30 9 5

0 0 0 0 8 4 4 0 2 1 0 0 0 0 0 4 2

17 13 3 13 10 1 2

20 12 6 2

64 42 15 7

organi c d i sturbances of the vocal fol ds show i n about 30� no de­vi ati ons of aerodynami c data . To what extent th i s i s connected wi t h t h e degree of the di s turbance wi l l be di scussed.

As far as Group I I is concerned , most of the aerodynami c dev iat ions were observed in pres s ure and effi ­ci ency va l ues . Only i n two out of ni ne dev iant cases the fl ow was devi ant , despi te the fact that the gl otti s remai ned open in al l cases .

In Group I I I , devi ant experi ­mental data were found i n the fl ow as wel l as i n the subgl ott ic

107

pressure data .

5.4

5 . 4 . 1

Results of all measuring

series in all patients

I ntroducti on

The aerodynami c data estab l i shed in pat i ents wi l l be d i s cussed i n re l at ion to c l i n i ca l symptoms re­vea l ed at l a ryngoscopi c exam­i nat ion . We di s ti ngu i s h two forms of gl otti s cl os ure : - -

a . The stati c o r quas i -stati c gl otti s c los ure i n preparati on

for a phonation ( zero fl ow ) . b . The dynamic gl ott i s c l os ure

duri ng phonati on , wh i ch on ly ca n be observed a t s troboscop ic examinat ion ( e ffecti ve non-zero fl ow ) .

The nomencl ature used for the descri ption of sound qua l i ty i s restri cted by us i n v i ew of the d i fficul ty in f i ndi ng terms wh i ch have the same meani ng for al l readers .

W ith the term abnorma l phonatory pattern we wi l l des i gnate the ex­terna l ly vi s ual symptoms of an i ncorrect type of b reath i ng , s uch as upper chest or c l a v i cu l a r breath i n g , wi th excess i ve us e of anteri o r and/or pos terior strap muscl es etc . duri ng phona t ion .

1 08

5 . 4 . 2

5 . 4 . 2 . 1

GROUP I , Pat i ents s uf­feri ng from orga n i c d i sturbances o f the voca l fo l ds

I ntroduct i on , d i v i s i on i n s ubgroups

In 42 out of 64 pati ents , an organ ic d i s turbance of the l a rynx coul d be establ i s he d . The character of the d i s turbances di verged from s l i ght hyperaemi a of both voca l fol ds to swol l en fol ds wi th l euko­pl ak i c a l terati on and severely hyperp last ic ventri c u l a r fol ds , wh i c h duri ng phona t i on nearly compl etely cover the true voca l fo l ds .

I n Tab l e 5-4 , the 42 pati ents ha ve been arran ged accordi ng to the cha racter of the i r c l i n ica l symptoms . I n the last ment ioned s ubgroups , the d i agnos i s was based ma i n l y on data from h i s to l ogica l exami nations .

Whether or not regress i on l i nes are devi a t i n g appea rs to be rel ated to the degree of d i s turba nces o f t h e voca l fo l ds . I n cases of hyper­aemi c vocal fol ds , a l l regres s i on l i nes l i e wi thi n the reference a reas . In more s evere di s turbances , nearl y a l l regress i on l i ne s are de vi ant .

Table S-4 . Classification of the regression lines from the 4 2 patients

with organic disturbances of Patient Group I .

org a n i c di s turbances one or more regress i on l i nes a l l regress i on 1 i nes outs i de reference a reas w i t h i n reference a reas number of pat .

hyperaemi a 0 oedema 3 vocal fol d nodu l es 8

pol yps , cys ts 6

papi l l omas 2 c h ron . hyperp l a s t i c 5 l a ryngi ti s , l eukopl ak i a ca rei noma 6

As fa r as treatment i s concerned , surgi cal i nterventi o n , vo i ce tra i n i ng , or a comb i nation of them have to be cons i dered .

I n so-cal l ed secondary orga n i c d i s turbances , e . g . hyperaemia , oedema , or nodu l es of the voca l fo l ds , and sometimes a l so i n hyper­p l a s t i c l a ryng i t i s , practi cal ex­peri ence shows that i mprovement may often be achi eved by voi ce tra i n i ng .

I n cases of organi c di s turbances , s urgi cal trea tment i s the pre­va i l i ng approa ch . Surgery i s cer­ta i nly i nd i cated whenever the d i s -

Pati ent number Pati ent No . o f pat .

3 35 , 5 3 , 6 1 , 63 3 19 ,

7 , 1 0 , 40 , 42 , 4 3 , 44 , 46 , 5 1 , 5 5

8 , 15 , 21 , 34 , 28 5 7 , 60 3 3 , 39 0 4 , 25 , 6 5 , 66 0

67 1 1 , 12 , 1 3 , 16 , 50 18 , 32

turbance prevents or h i nders a tota l dynami c c l os ure of the gl otti s .

No .

48 , 29 , 49 ,

For a general s urvey of current voi ce therapeuti c methods �te refer to Dams te ( 1973a ) , Damste and Lerman ( 1975 ) , Cooper ( 1973 ) , Cooper and Cooper ( 1977 ) , Wendl er and Sei dner ( 1977 ) , and for spe­c i f i c methods e . g . to Ve l dkamp ( 19 73 ) , Cobl enzer and Muhar ( 1976 ) , and to Dal hoff and Ki tzi ng ( 19 7 7a , b ) .

Surgi cal treatment nowadays gen­era l ly is carried out accord i ng to the mi crol a ryngeal method i n-

109

62 45 54 , 58

Table S-5 . Three patients, from Group I, with hyperaemia vocaL fo lds .

Data for flow , pressure , and efficiency , derived from the regression

lines at the middle of the dynamic range ( Im

) . Tne interval is the time

between two successive measuring series . The value of �Erel

indicates

the difference between successive Erel

values . For these three patients ,

all regression lines lie within the reference areas .

Pati ent i nterva l Im No . months dB

35 74 48 75 . 5

12 74 62 78

fl ow ml/s

188 153 164 204

traduced by Kl ei nsasser ( 1968 ) .

press . kPa

0 . 72 l. 15 0 . 88 0 . 78

The pat ients s ufferi ng from a l a ryngeal carci noma recei ved rad io­therapeut i c treatment . In one Patient , No . 16 , s ufferi ng from a re l apse of a l aryngeal carci noma , l a ryngectomy �1as necessary .

I n Pati ent No . 65 , from the s ub­group chroni c hyperpl asti c l aryng i t i s and/or l eukop lak i a , a l a ryngea l carci noma �tas estab l i shed after repeated b i ops i es a few months after the fi rs t measuri ng seri es and a 1 a ryngectomy vtas performed .

5 . 4 . 2 . 2

1 10

Di s cuss i on on the experi mental data

effi c . x10-5

2 . 7 2 . 9 2 . 5 5 . 7

Hyperaemia

- 1 . 4 - 2

1 . 7 - 0 .6

therapy

+ 0 . 3 voi ce tra i ni�

Th ree Pati ents , Nos . 35 , 4 8 , and 6 2 , showed s l i ght deviati ons of the voca l fo l ds . Thei r re­gress i on l i nes a l l l ay wi thi n the correspond i ng reference a rea , wh i ch a l so was the case i n the second measuri ng seri es of Pati ent No . 48.

The val ues for the fl ow , press­ure , and effi c i ency and the re l a ­t i ve effi c i ency a t Im a re shown in Tab l e 5-5 .

The va l ues for E rel demonstrate that the dev i a t i ons from the ref­erence regress i on l i ne a re sma l l .

A second measuri ng series o f Pati ent N o . 48 res u l ted i n va l ues pract i ca l ly i dentical wi th those from the fi rst seri es . Th i s corre-

Table S-6 . Six patients, from Group I, with oedematous voca l folds .

(For legends see Table 5-S . ) The subdivision i n deviant and non-deviant

regression lines is made with respect to the first measuring series . A

calculated value at Im

lying outside the reference areas has been marked

in italics . An asterix designates a significant efficiency change

( P<O . lO ) .

Pati ent i nterval No . months

dev i ant 53 6 1

6 3

non-dev i a n t 1 9

2 9

45

7

27

4 1 1

2 1

1 1

79 . 5 79 . 5 84 . 5 70 . 5 74

73 78 75 72 . 5 77 81 72

fl ow ml /s

1 75 361 235 4 1 8 297

216 132 181 239 283 254 244

sponded wel l wi th the c l i ni ca l fi ndi ngs a n d t h e symptoms of the pat i ent. The vo i ce tra i ni ng wh ich th i s pat i ent was gi ven , but di d not real l y wanted , y i e l ded no improvement .

Oedema

I n three of the s i x pati ents o f th i s s ubgroup , see Tab l e 5-6 , one or two regress ion 1 i nes �1ere de-

pres s . kPa

effi c . x10- S

therapy

1 . 21

1 . 34 1 . 33

6 2 . 7

1 3

- 1 . 4 - 4 . g - 1 . 2

adv ice vo ice t ra i ni ng

+ 3 . 7* 0 . 68 0 . 86

0. 6 1 . 4

- 5 . 9 - 4 . 2

surgery + + 1 . 7 vo i ce t ra i n i ng

0 . 83 1 . 02 0 . 98 0 . 66 0 . 63 0 . 88 0 . 59

1 . 6 6 . 8 2 . 6 1 . 6 4 . 1 8 . 1 1 . 6

- 3 0 . 1

- 2 . 2 - 2 . 6 - 1 . 5 - 1 - 2 . 4

adv i ce + 3 . 1* adv i c e - 2 .3*

surgery + 1 . 1

adv i c e - 1 . 4

v i a t i ng . The regress ion l i nes from the other three pati ents l ay just wi th i n the reference areas .

The characteri s t i c val ues for fl ow , pressure , and effi c i ency at I a re al so gi ven i n Tabl e 5-6 . m

I n these pat i ents no c l ear re-l a t i on appea rs between the ex­tens i on of the oedema and the de­vi at ions i n the aerodynami c pattern . The un i l ateral oedematous ti ssue of Patient No . 29 was much

1 1 1

more extens i ve than the mi nimal oedema a l ong the marg i ns of the fo l ds in Pati ents Nos . 53 and 6 1 .

I n Patient No . 29 , the oedematous t i s s ue was removed by m i c rosurgi cal i nterventi on . Pati ent No . 61 was gi ven vo ice tra i ni ng . Patient No . 63 , after removal of the oedematous t i s s ue of the ri ght vocal fo l d , recei ved voi ce tra i n i ng duri ng a short peri od . Th i s pat i ent was sati s fi ed wi th the i mp rovement to such an extent that she rejected a second i n te rventi on , i ntended to remove the oedematous ti s s ue from the l eft vocal fo l d .

I n three Pati ents ( Nos . 19 , 45 , and 53 ) , we cou l d only gi ve an adv i ce on more effecti ve use of the i r voi ces .

The g reatest i mprovement was observed in Pati ent No. 61 . I n the second meas uri ng series al l re-g ress i on l i nes fe l l wi thi n the reference areas .

Pati ent No . 19 showed remarkabl e changes o f effi c i ency . I n the fi rst measuri ng seri es , the external ly vi s ual phonatory pattern was very tense . At the second seri es , th i s was not the case anymore , wh i l e an obvious improvement i n the eff i ­c i ency cou l d be establ i shed . Pho­nat i on gave l ess troub l e and the symptoms had decreased . Du ri ng the thi rd seri es , performed because

1 12

the pati ent aga i n had compl a i nts , oedema of the vocal fol ds and a tense phonatory pattern coul d be observed once more .

I n summa ry , i t may be concl uded that in pat i ents with oedema of the vocal fo l ds the aerodynami c data provide a varyi ng p i c tu re wi thout a c l ear re l ation to the degree of pathol ogi cal di sturbance . The presence of oedema may res u l t i n a dynami c gl otti s c l osure duri ng phonation so that the ae rodynami c data are practi cal l y norma l .

ilodu "les

Thi s subgroup compri ses twel ve pat i ents , of wh i ch ei ght di d show dev i ant regress ion l i nes and fou r d id not , see Tabl e 5-7 .

W i th respect to the res u l ts of the fi rst measuring seri es i t can be said that the dev iat ions , rep­resented i n Erel , appear to be greater than i n the cases wi th cl i ni ca l l y l ess severe symptoms l i ke hyperaemi a and oedema .

I n ei ght pat i ents , the vocal fol d nodules �1ere removed by mi cro­surg i cal i nterventi on ; in fi ve of them ( Nos . 7 , 44 , 46 , 49 , and 5 1 ) , the cl i n i ca l di agnos i s of vocal fol d nodu l es ( Sangerknotchen) 1�as hi s to l ogi cal ly confi rmed . I n the

Table 5- 7 . Twe lve patients, from Group I, with voca l fo ld nodules .

( For legends see Table S-6 . )

Pati ent i nterva l No . months

fl ow ml /s

press . kPa

effi e . x l0- 5

therapy

dev i ant 7

10

40

42

44

46

51

55

non-deviant 3

49

54

58

4 15

17

13

2 9

12

10

1 1

6

12

9 12

8 2

75 . 5 7 7 . 5 82 . 5 76 79 74 . 5 75 . 5 79 78 76 76 72 78 . 5 76 73 83 76 . 5

72 . 5 79 . 5 73 76 78 81 74 . 5 76 78 . 5 81 . 5

534

386 464 346 329 256 4 74 3 10 4 68 459 295 194 142 467 329 512 254

1 74 242 273 234 245 299 320 325 193 256

1 . 1 5

1 . 19 1 . 8 0 . 98

1 . 33 1 . 1

1 . 24 0 . 89 1 . 2 0 . 9 7 0 . 89 0 . 92 1 . 21

1 . 4 1 . 0 2

1 . 62 1 . 04

0 . 64 0 . 95 0 . 67 0 . 66 0 . 96 1 . 59 1 . 1

0 . 65 0 . 62 0 . 83

0 . 8

1 . 8 3. 1 1 . 7

2 . 6 1 . 4

0 . 9 4 . 1 1 . 6 1 . 3 2 . 2 1 . 3 6 0. 9 0 . 9

3 . 5 2 . 4

2 . 3 5 . 6 1 . 6 3 . 7 3 . 9 3 . 8 1 . � 2 . 7 8 . 6 9 . 6

- 7 . 4 5 . 4

- 6 . 2 - 4 . 7 - 4 . 7 - 4 . 4 - 7 . 2 - 2 . 7 - 6 . 1 - 5 . 9 - 3 . 6 - 3 . 4 - 0 . 8 - 7 . 5 - 5 . 7 - 6 - 3 . 4

1 . 1 - 1 . 7 - 3 . 1 - 1 . 3 - 2 . 3

4 . 3 - 5 . 4 - 2 . 6

0 . 8 - 0 . 6

s urgery voi ce tra i ni n g

- 0 . 8 voi ce t ra i n i ng + 1 . 5

advi ce + 0 . 3

adv i ce + 4 . 5*

voi ce tra i n i ng + + 0 . 2 surgery + 2 . 3*

surgery + 2 . 6*

s urgery + 1 . 8

voice tra i ni ng + + 2 . 6* surgery

voi ce tra i ni ng - 0 . 6

s urgery + 1 . 8

s urgery + 2 * voice tra i n i ng

- 1 . 1 vo i ce res t +

+ 3 . 4* s i ng i ng l essons - 1 . 4

rema i n i ng th ree pa ti en ts , a s l i ght pa ra kera tos i s /acanthos i s of the l a ry ngea l mucos a ( Nos . 3 and 54 ) was es tabl i shed i n tl'/0 cases , wh i l e

a t i ssue sampl e from Pati ent No . 5 5 sho1'1ed norma l 1 a ryngea 1 mucosa .

I n nearly a l l pati ents from th i s subgroup , the 1 a ryngoscopi c exam-

1 1 3

i nation proved remarkably that both and was rece i vi ng s i ng i n g l es sons . before and after the removal (or We advi ced the pati ent to ma ke spontaneous di s appearance) of the a l ess i ntens i ve use of h i s vo i ce . nod u l es the g lotti s showed an i n- Voice t ra i n i ng was cons i dered not compl ete cl osure at the dorsal to be necessary , because he re-pa rt. Th i s fi nd ing wi l l be d i s - cei ved s uffi c i ent voi ce tra i n i ng cussed i n more deta i l i n Secti on in h i s s i ng i ng l essons . The im-5 . 4 . 3 . provement of the effic i ency i n th i s

case was ma i n ly to be a scr ibed to Si gni fi cant improvements appeared

to have occurred i n Pati ents No . 42 ( 4 . 5 dB) , No . 58 ( 3 . 4 dB ) , No. 55 ( 2 . 6 dB } , No. 46 ( 2 . 6 dB) , and No . 44 ( 2 . 3 dB ) .

I n Pati ent No . 42 , showi ng the grea tes t i mprovement wi th a 4 . 5 dB i ncrease in effi ci ency , the nodul es of the voca 1 fo 1 ds were not re­moved ; i ns tead , she wa s gi ven voice tra i n i ng . In th i s pati ent severe m i s use of the vo i ce ( rows , shouti ng ) , i n connection w ith do­mes t i c probl ems , had pl ayed an i mportant rol e . At the time of the second seri es her probl ems and the mi s use of her vo i ce had decreased , wh i ch i n our op i n ion exp l a i ned the favourabl e res u l t .

The improvement i n Patient No . 58 , a student of the Academy of Mus i c , may be expl a i ned from the fact that in the peri od of the fi rs t measuri ng series the pa ti ent stra i ned h i s vo i ce . When h i s com­pl ai nt s tarted , he was conductor of a cho i r , gave mus i c l essons ,

1 14

the decreas e of a i r consumptio n . The i mprovement observed i n

Pa t ient No . 5 5 cannot be a ttri buted to reco very of the orga n i c struc­ture of the vocal fol ds . A t the surgi cal i ntervention only very l i ttl e t i s s ue was removed , wh i ch appea red to be normal l a ryngea l t i ssue . The i ncrease i n the eff i ­ci ency due t o the decreas e o f the flow val ues has to be ascri bed ma i nly to the effect of the vo i ce tra i n i n g .

I n Pat i ent No . 46 , the vocal nodules were removed by mi c ro­surgery . From the course of the di sease may be deducted , that i n th i s pa t ient , as i n Pa tient No . 42 , an emoti onal ly condi t i oned fa ctor pl ayed a ro l e . She changed her j ob , wh i ch , together with the s urgi ca l i ntervent i on , res ul ted i n an i m­provement of vo i ce producti o n .

I n Patient No . 54 , a deterio­ra tion was observed , name ly wi th respect to the press ure va l ues .

Table 5- 8. Seven patients, from Grat1p I, with polyps and/or cysts .

(For legends see Table 5-6 . )

Pat i ent i nterva 1 Im fl ow press . effi e . Erel t.Erel therapy No . months dB ml /s kPa x 1o- 5 dB dB

dev i a n t B 75 . 5 341 1 . 32 1 . 1 - 6 . 1 s urgery

3 76 174 0 . 89 3 . 7 - 1 . 3 + 4 . 8* 15 81 217 2 . 63 3. 2 - 5 . 1 s urgery

3 80 . 5 348 1 . 14 4 . 1 - 3 . 7 + 1 . 4 21 78 . 5 4 20 1 . 17 2. 1 - 5 . 4 s urgery

4 73 . 5 332 1 . 29 0 . 8 - 6 . 6 - 1 . 2 34 77 . 5 541 1 . 03 1 . 5 - 6 . 3

1 76 . 5 472 1 . 08 1 . 3 6 . 3 0 surg . + vo i ce tr . 2 7 5 . 5 352 0 . 67 2 . 2 3 . 3 + 3 * vo i ce tra i n i ng 8 7 7 . 5 377 0 . 92 2 . 3 4 . 2 - 0 . 9 vo i ce tra i n i ng

57 7 2 . 5 125 1 . 39 1 . 5 - 3 surgery 60 73 370 2 . 1 5 0 . 4 - 9 . 5 surgery

3 7 1 . 5 254 1 . 35 0 . 6 - 6 . 4 + 3 . 1*

non-devi ant 28 82 243 1 . 04 9 . 1 - 1 . 2 s urgery

The t i ssue samp l e from th i s pa ti ent Polyps and/or cysts

sho�1ed onl y few aberrations . At l a ryngos copi c exami nation i t was obs erved that the dorsal part of the g l otti s , the chi nk , rema i ned rather wi de ope n . Only by great mus c u l a r effort , wi th h i gh s ub­gl otti c pressures , the pati ent was ab l e to produce a moderate ly l o ud vocal sound . Voi ce tra i n i ng y ie l ded no i mprovement of th i s d i s tu rbance .

Th i s subgroup compr i ses s even pati ents , the regress i on l i nes of s i x patients were devi ant , see Tabl e 5-8.

The c l i ni ca l symptoms wi thi n th i s subgroup vary . Fi rstl y , i n al l pa t i ents a surg i cal i nterventi on wi th removal of the growths was performed .

I n two Pa t i ents , Nos . 8 a nd 60 , a sol i d ti ss ue formation was s een on one of the vocal fol ds .

1 1 5

)

0 100

E ( 10 ')

10 0

0

-

f-.--

� 1 "'"[,/// ··� / /

Uow.•

--: � � -==--I -II I I

" " I I I I I I I I I I I I I I I� " "

w / I I I .

� }t--& il I : 1 " II

llow.b / A .. L

/ �"1 / f"·' / Pr!!-v......-/ v

-; -

v

1.0 q (l/s)

O S

0.2

0.1

0.05

1 0 p (kPa)

5

2

0.5

0.2

0. 1 60 70 /\ 80 90 100 0.1 l (dB)

Figure S- 2 . Depiction o f the regression lines

for flow , pressure , and efficiency

from both measuring series in

Patient No. 8 , represented with

the corresponding reference re­

gression lines . The data o f the

first measuring series have been

marked with a , those of the second

series with b . After the removal

of the polyp, pressure values as

well as flow values have decreas ed .

The efficiency was raised and lies

close to the reference regression

line .

H i s tol ogical exami nat i on of mi c ro­surgi cal ly remo ved t i s sue revea l ed scl erot i c hemangi oma .

Patient No. 15 had a cys t and

116

No . 21 a pol yp , the c l i n i ca l d i a g­noses bei ng confi rmed by h i s to­l ogi cal exami nati on .

I n the Pati ents Nos . 34 and 5 7 , wi th a cl i ni cal d i agno s i s o f polypous swol l en voca l fol d s ( polypos i s l a ryng i s ) , these pa­ti ents proved on hi stol ogica l exami nati on to be sufferi ng from severely oedematous swol l en l a ryngea l mucosa , wi th no t rue pol yps bei ng formed .

I n Pati ent No . 28, the only case in thi s subgroup with no de viant regress i on l i nes , hi stol ogi cal exami nation revea l ed a chron ic ul cer .

The regres s i on l i nes from both measuring seri es of Patien t No . 8 a re represented i n Fi gure 5 - 2 .

The sol i d growth o n one o f the vocal fol ds of th i s pat i ent was l ocal i zed at the free medi a n edge . Th i s polyp h i ndered of course a proper c losure of the g lott is duri ng phonati o n . On the other hand , i n Pati ent No . 60 , the pol yp was s i tua ted on the c rani a l s i de of a vocal fol d . The med ian edges of both vocal fol ds s howed no di s ­turbances , and thus a good c losure of the g lotti s cou l d take pl ace .

Compa ri ng these two cases , i t i s cl ear that Pati ent No . 8 not only d isp l ayed a more seve re d i s -

Table 5-9 . Two patients, fl'om Group I, with papil lomas .

(For legends see Table 5-6 . )

Pa tie nt i nterval Im fl 0�1 press . effi e . E rel llEre 1 therapy No . months dB ml /s kPa x10-S dB dB

dev i a nt 33 79 . 5 234 2. 83 1. 9 - 6 . 3 s urgery

1B 72 1 12 1 . 41 1 . 4 - 2 . 8 + 3 . 4* 7 7 2 . 5 100 1 . 27 2 - 1 . 7 + 1 . 1

39 78 . 5 194 1 . 5 3 . 5 - 3 . 1 ( surgery ) 17 67 266 o . n 0 4 - 5 . 7 - 2 . 6*

turbance of the voi ce but a l so fel t growths . more uncomfortab l e i n speak i ng than Patient No. 60 , no doubt a s i mp l e conseq uence o f the pos i t i on of the growth . I n the post-oper­ati ve meas uri ng seri es , Pati ent No . 8 was free of comp l a i nts and produced no rmal phonati o n , whereas Pati ent No . 60 was somewha t re­l i eved of d i s comfort i n phonati ng . Des p i te the s i gni fi cant i ncrease in effi c i ency , she s ti l l s howed devi ant regres s i on l i nes for press ure and effi ci ency .

I n two cases a s i gni fi cant im­pro vement a fter surgi cal treatment was found . Genera l l y , as fa r as the resul ts of s urgi cal i nter­venti on a re concerned , i t appears that the avera ge val ue of Erel is pos i ti ve . Subjecti vely , mos t pat i ents experi enced , that pho ­nation went more eas i ly a�d was l es s ti ri ng after removal of the

Papil lomas

In both Pati ents , Nos . 33 and 39 , wi th papi l l omas of the adu l t type l oca l i zed a t several pl aces in the l arynx , the pres sure re­gress i on l i nes appeared to be devi ant i n the fi rst meas uri ng seri es , see Tabl e 5-9 .

The data show tha t the subg l otti c pressures a re h i gh , 1vhereas the fl ow val ues at Im have about avera ge l evel s .

I n Pati ent No . 33 , a s i gni fi cant i mrrovement coul d be establ i shed , even one and a ha l f year a fter mi crosurgi cal removal of the papi 1 1 oma s . �1u l t i p 1 e so 1 i ta t·y papi l l oma s on the true vocal fol d had been removed by mi crosu rgery . From the aerodynami c data , i t

1 17

Patient No .

deviant 4

2 5

6 5 66 6 7

Table 5- 10 . Five patients, from Group I, with chronic hyperpZastic

Zaryngitis and/ol' ZeukopZakia.

(For legends see Table 5-6 . )

i nterva l Im fl ow press . effi e . Erel llErel therapy months dB ml /s kPa x1o- 5 dB dB

7 1 . 5 196 0 . 78 1 . 3 4 77 . 5 290 0 . 78 3 . 6 9 79 244 0 . 75 6 . 2

80 . 5 300 2 . 1 2. 6 13 79 . 5 161 1 . 45 5 . 5

7 1 332 1 0 . 5

69 . 5 375 3 . 99 0 . 1

72 . 5 167 1 . 4 1 1 . 1

appea rs that the fl ow va l ues as we l l as the pressure val ues had decreased cons i derab l y . These data corresponded wi th the patient ' s s ubjecti ve experi ence o f l esser effort requi red to phonate . I n a th i rd seri es , seven months l ater , th i s improvement o f the aerodynami c data appeared to have conti nued . The regress i on l i nes a l l l i e wi thi n the reference a rea s .

I n Pati ent No . 39 , the fi rst meas uri ng series was performed after mos t of the papi l l omas on the true voca l fol ds had been re­moved for hi s tol o g i ca l exami na t ion . Therefore, the res u l t of the fi rst measuri ng seri es of th i s pa t i ent i s compa rabl e �1i th the second meas uri ng seri es of Pati ent No . 3 3 .

1 18

2 . 8 vo i ce tra i n i ng 2 . 4 + 0 . 4 vo i ce tra i n i ng

- 0 . 9 + 1 . 5 5 . 7 voice tra i n i ng

- 1 . 8 + 3 . 9* - 6 . 4 - 1 3 . 5 voi ce tra i n i ng - 4 . 3

The second seri es o f Pat i ent No . 39 showed that a deteri ora t i on had taken pl ace , the voi ce hav ing be­come weaker and a hi gher f l ow va l ue and deviant press ure va l ues at Im havi ng devel oped . At l a ryngoscopy , the voca l fol ds appeared free of papi l l omas , but were l es i oned by the biops i e s , which caused i ncom­pl ete c l osure at phonat ion . In the fi rs t measuri ng seri es , reacti ve oedema as a resu l t of the b i ops i e s pos s i b ly pl ayed a rol e , cau s i ng a fa i rl y proper c l osure of the gl otti s .

Ch!'cn:i� hype;•p Zas t·i� la!'y;::;i ti::

anci/o!' leo<.l:opld:ia

Thi s s ubgroup of fi ve pati ents ,

see Tab l e 5- 10 , al l of whom ap- 100 0

peared to have one or more deviant E( lo·•,

regress i on l i nes i n the fi rs t measuri ng seri es , showed a vari ety of c l i ni cal symrtoms .

Pati ent No 4 had l eukop l a k i a o n the vocal fol ds wi thout hyper-p las i a of the ventri cul a r fol ds , whereas i n Pati ent No. 66 the vocal fo l d s had s i nce yea rs been severely swol l en , wi th very hyperp l a s ti c ventri cul a r fol ds . Extensi ve l euko­pl a k i c areas were present on the true vocal fo l ds as wel l as on

10 0

0

1

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::::::--r �low.b / I I I .,£,., I I I I r----I I I ! / I I I i//·r I

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I I I I I I I I I I 1 :

the ventri cul ar fol ds . I n both pati ents , a very tense phonatory pattern coul d be observed .

0 .1 60 70 /.811'-. 90 100 ! (dB)

Figure 5- 3 .

1 .0 q (lfs)

0.5

0.2

0.1

0.05

1 p (kPa)

5

0.5

0.2

0.1

I n Pati ent No . 66 , the orga n i c cond i t i on of t h e l a rynx h a d been

Depiction of the regression lines

for flow , pressure , and efficiency

changed so much tha t the vocal from both measuring series in Pa-

fol ds coul d s ca rcely be b rought tient No . 25 , represented with the

to v i bration . The ventri c u l a r fo l ds corresponding reference regression

h i ndered the true vocal fol ds i n lines . The data of the first meas-

the i r act i o n . The rel ati ve effi - uring series have been marked with

c i e ncy va l ue was very l ov1 , a , those of the second series with

- 13 . 5 dB . b . In this patient Hith chronic

Pati ent No . 4 v1as gi ven voi ce hyperplastic laryngitis , the phc-

tra i n i n g , and the phonatory pattern natory pattern improved in the

i mproved but a s i gn i fi cant i ncrease course of about one year, partly

i n the effi ci ency cou l d not be as the result of voice training .

establ i shed . The improvement i n aerodynamic data

can be observed from the decrease

Both meas uri ng seri es from Pa­ti ent No . 25 represent i ntermed i a te stages i n an i mprovi ng phonatory pattern wi th s i mul taneous i mprove-

of the flm-; values and , to a lesser

degree , of the pressure values .

The relative efficiency had in­

creased by 3 . 9 dB .

1 1 9

ment of the l a ry ngeal o rgani c condi t i o n , see Fi gure 5-3 .

Th i s pat i ent had been c l a s s i fi ed i n thi s s ubgroup because ni ne months pri or to the fi rs t measu ri ng seri es a l aryngi ti s wi th l euko­p l a k i a had been establ i s hed . Mi c ro-scop i c exami nat i on of the t i s s ue remo ved at di rect l a ryngoscopy yie l ded a d i a gnos i s of severe dyspl as i a , wi th the comment adde d , " I t i s a ma tter of op i n i on whether it is severe dysp l a s i a or carci noma in s i tu . " Radi otherapy was con­s i dered , but fi nal l y not appl i ed . The pat ient was asked t o come i n for regul a r fa l l 01�-up exami nations . He was very pl eased to make these vi s i ts , fee l i ng reas s ured when everythi ng sti l l appea red to be a l l ri ght . Gradual l y , the vo i ce i mproved and the l aryngi t i s symp­toms di s appea red . The very tense phonato ry pattern , wh ich was ap­parent from the begi nn i ng , st i l l rema i ned and the ave rage spea k i ng vo i ce pi tch l evel was rema rkably h i gh . Th i s can be seen as a s i gn of hi s emoti onal i ty . The dynami c potenti a l i t i es of the vo i ce ( pho­netogram) , howe ver , v1ere good . V o i ce tra i n i ng was s ta rted , but ,

i t appea red that the p ressure va l ues were l ower , Th i s y ie l ded an u l t imate improvement i n rel at i ve effi c i ency o f 3 . 9 dB .

Squamous carcinoma

Thi s subgroup compri s e s seven pat i ents wi t h a squamo u s carci noma of the l a ryngeal mucosa , see tab l e 5- 1 1 . S i x o f these seven pati ents had a squamous carci noma of the vocal fo l ds . There were di fferences in the s i te and extens i on of the carci noma . In Pati ent No . 50 , the true vocal fol d s were not a ffected , the tumour was s i tuated on the i nner s i de of the epi g l o tt i s and l eft the vocal fol ds fre e . In t h i s pa ti ent the regress i on l i nes were not de vi ant .

I n a l l pati ents o f the devi ant grou p , we found a very tense pho­natory pattern . At l aryn goscopi c examination hypertrophi c ventri -cu l a r fol ds were found . Moreover , duri ng phona tion these ventri cu l ar fo l ds were more or l ess b rought to adducti on and , therefore , i n­terfered wi th the correct vi bra t i on pattern of the true voca l fo l ds .

due to an intercurrent di sease , I n Pati ent No . 1 1 , the patho l -soon stopped . At the second seri es , agi s t i n i t i a l l y d i a gnosed the the phona tory pa ttern 1·1as much l es s bi opsy a s s eve re dyspl a s i a . Afte r tense . From the aerodynami c da ta , a second opi n ion , the pathol ogi s t ' s

1 20

Table 5- 1 1 . Seven patients, from Group I, with squamous eareinoma.

(For legends see Table 5-6 . )

Pati ent i nterva l Im fl ow pres s . effi e . Erel liEre 1 therapy No . months dB ml /s

dev i ant 11 73 354

24 77 . 5 3 14 12 72 . 5 1 7 1

19 80 98 13 7 1 307 16 75 489

18 80 . 5 364 2 1 7 5 232

32 76 . 5 249 13 79 . 5 145

non-devi ant 50 75 205

advi ce was to con s i de r the di s ­turb ance as an early i nvas i ve s quamous carci noma . Shortly there­a fter , new b i ops i es l ead to the d i a gnos i s of carci noma i n s i tu . Rad i o therapy was cons i dered . but fi na l l y not app l ied . Based on the undi s turbed cl i ni cal appea rance of the vocal fo l ds , i t was deci ded not to opera te , but frequently to fol l ow up the pati ent . In retro­spec t , we may a s s ume that the ex­ten s i on of the carci noma had been so l i ttl e tha t i n ta k i ng the b i o p s i es , al l patho l o g i ca l t i s s ue had been removed . The aerodynami c

kPa x10-5 dB dB

0 . 9 ? 0 . 8 - 5 . 8 b i opsy 1 . 1 2 . 3 - 4 . 2 + 1 . 6 1 . 88 0 . 8 - 5 . 7 rad i otherapy 1 . 58 9 . 3 0 . 2 + 5 . 9* 0 . 7 0 . 8 - 4 . 5 rad i otherapy 1 . 28 0 . 7 - 7 . 7 1 . 45 3 . 1 - 5 rad i othera py 0 . 95 2 . 1 - 3 . 2 + 1 . 8 1 . 58 1 . 01

0 . 78

1 . 6 - 5 . 1 rad i otherapy 8 . 8 0 . 2 + 5 . 3*

2 . 9 - 1 .8

pa ttern was deviant, a l though the vocal fol ds at the moment of the measuri ng seri es were hardly a f­fected . At stroboscopi c exami nati on the vi bration pattern of the ri ght vocal fol d seemed to be i nfl uenced by ri g i d scar ti s sue . The phonatory pattern was very tense and remark­ably hyperk i neti c .

The pa ti ent frequently vi s i ted our out-pati ent department for fol l ow- up exami nations . The ap­pea rance of the vocal fol ds and the fi nd i ngs at stroboscopy i n l ater years ga ve no reason for further i nvesti gations . I n the two

1 2 1

yea rs between the fi rst and second meas uri ng series , the voi ce grad­ua l l y became l es s hoarse . I n emotional ly stressed s i tuati ons though , the pati ent s ti l l had periods in whi ch h i s vo i ce sounded hoarse . Duri ng the second meas uri ng seri es , the vo i ce sounded pract i ­cal l y normal . The vocal fo l ds had a normal appea rance and the hyper­trophi a of the ventri cul ar fo l ds had decreased cons i dera b l y . The effi c i ency of the l a rynx i mproved , but the subgl otti c press ures re­mai ned rather h i g h .

For the i nterpreta ti on o f the aerodynami c da ta it i s of i mport­ance to note that the va l ues for press ure and effi c i ency were devi ant , whereas the vocal fol ds sho�ted on 1 y few aberrati ons . He may concl ude from these obser­va tions that someti mes there i s no obv i ous rel at ion between the aerodynami c da ta and the 1 a l·yngo­scopi ca l ly vi s i b l e cond i ti on o f the vocal fol ds . Sometimes the appearance of the voca l fo l ds i s much better than the aerodynami c data woul d s ugges t .

Des p i te the sma l l devi ati ons o f the vocal fo l d s , the rel ati ve eff i ­c iency i n Patient No . 1 1 i s - 5 .8 dB . The hypertroph i a .of the ventri cul ar fol ds and the fact that

122

these fol ds nearl y compl ete ly cover the true vocal fo l ds dur i ng pho­nati on , has a great i nf l uence on the effi c i ency of vo i ce producti on . The appearance o f hypertroph i a o f the ventri cu l ar fol ds a t l a ryngo­scopy o ught a l so to be j udged as a s i gn of hyperfunction . Th i s hyperfunction wi l l a l so be found in the externa l l y v i s i b l e phonatory pa ttern .

I n Pati ent No . 18 , we observed a very l i mi ted l es i on on one of the vocal fol ds . The h i s tol ogi ca l exami nati on l ead to the di agnos i s o f we l l di fferenti ated sq uamous carci noma . The pati ent was g i ven radi otherapy , and the vo i ce grad­ua l ly improved . At the s econd measur ing seri es , the voca l fo l ds were norma l , moreover , the hyper­troph i a of the ventri c u l a r fol ds had decreased .

Both Pati ents ( Nos . 11 and 18) s howed a very tense and hyper­k i neti c phonatory pattern , wi th cos tal and sometimes pa radoxi ca l respi rati on . I n i t ia l ly the vo i ces were very dul l , wi th much wi l d a i r . After X- ray treatment , the fl m� va l ues were not deviant , both voi ces sounded c l ear and the pho­natory pattern was l ess tense .

The great i mprovement i n the aerodynami c data of the Pati ents

Nos . 12 and 32 i s remarkabl e . I n Patient No . 1 2 , the sudden

improvement of the vocal symptoms was consp i cuous . The voi ce probl ems of th i s pa ti ent arose after an automobi l e acc i dent . I ni t ia l l y , the patient was aphon i c for some days , then the vo i ce returned . Laryngeal i nj u ry was out of the ques t ion . The vo i ce rema i ned hoarse and the a verage spea k i ng vo ice p i tc h l evel was remarkably hi gh (G3 , 195 Hz ) . Very severe hyper­trop h i c ventri cu lar fo l ds were ob­served at l aryngoscop ic examin­at ion . On one of the vocal fo l ds appeared to be a tumour , suspected of bei ng ma l i gnant . A bi opsy re­veal ed the di agnos i s of squamous carc i noma . The pat i ent wa s g i ven rad i o therapy .

I n i t i a l ly the phonatory pattern was very tense , �1i th hi gh and para­doxi cal respi ration and much wi l d ai r . Unti l shortly before the end of the X-ray treatment the voi ce rema i ned hi gh-pi tched and very hoa rs e . Even more rema rkab l e was the fact that the voi ce improved from one day to the next , the a verage s pea k i ng voi ce pi tch l eve l s i nk i ng to the usual l evel for men . In the second measuri ng seri es , the vo i ce was cl ea r , the vocal fol ds �1ere normal , and hypertroph i a o f t h e ventri cul ar fo l ds cou l d not

be observed anymore . The dynami c potenti a l i t i es a l so i ncreased , as is apparent from the i ncrease i n Im . Desp i te th i s i mprovemen t , the subgl otti c pressure remai ned rel a ­ti ve l y h i gh a n d dev i a n t . The eff i ­ci ency , however, i ncreased due to the decrease of the fl ow val ues .

Pati ent No . 32 had a l ong hi story of vocal comp l a i nts wi th a pro­nounced fear " that somethi ng was wrong with h i s throat" . A l ocal th i c keni ng on one of the voca l fol ds �1as found at l aryngoscopi c exami nati on . From the bi opsy ma­teri a l , the pa tho l og i s t reported "wel l di fferenti ated squamous carci noma wi th i nfi l trati ve gro�1th " . The phonatory pa ttern �1as very tense and hyperki net i c and vo i ce product i on demanded much effort . Rad iotherapy �1a s gi ven . At the second meas uri ng seri es , the phona tory pattern was s t i l l very tense . Ho�1ever , someti mes a more rel axed phonatory pattern coul d be observed . After treatment , the regress ion l i nes for subg l ott i c pressure and effi ci ency were not deviant anymore .

5 . 4 . 2 . 3 Concl us ions

We may summa ri ze our concl us ions about the pa ti ents i n Grour I as

1 23

fal l ows : --a . General ly spea k i ng , a re l at i on

exi s ts between the degree of c l i ni ca l l y observed di s turbances and the devi ati ons of the aero­dynami c pattern of vo i ce p ro­ducti o n .

b . T h e devi ati ons of t h e aero­dynami c data are often l a rger

than the organi c appearance of the vocal fol ds mi ght sugges t . Th i s

shows any i mprovement . e . The major ity o f the pati ents

wi t h vocal nodu l es s howed an i ncompl ete cl osure o f the gl otti s . Th i s fact seems to be more i mportant than the presence of the nodules i tsel f .

f . I f a n organ i c di sturbance hi nders a compl ete dynami c

cl osure of the gl ott i s and the fl ow i s about norma l , the subg l ott ic

seems to be s trongly corre l ated press ures commonly are found to with a tense and hyperk i net ic pho- be hi gh . The i nc reased s ubg lott i c natory pattern . Though i n some p ressure seems to be the conse-cases removal of the o rgan i c aber- q uence of the i ncreased muscul a r ra tion �tas s uffi c i ent to enab l e the effort necess a ry to effectuate pat i ent to real i ze a comp l e te dy- a proper cl osure of the gl otti s . nam i c c l os ure , v o i ce tra i n i ng was After removal of the organi c di s -ofte n neces s a ry to teach the pa- turbance a compl ete dynami c c los u re t i ent hovt to get r id of th i s estab- is pos s i b l e 1�i th l m�er s ubg lott i c l i s hed habi ts of hyperki neti c a n d press ure and f l ow va l ues . tense phonatory pattern .

c . Surg i cal therapy as wel l as vo i ce tra i n i ng , in general ,

may yiel d improvement of l a ryngea l effi c i ency .

d . Improvement of l a ryngeal e ffi -c i ency depends on the pos s i ­

b i l i ty of dynami c g lotti s cl osu r·e duri ng phonation . The res ul t of removi ng a po lyp from the free ma rgi n of a voca l fol d i s there for·e

5 . 4 . 3

5 . 4 . 3 . 1

GROUP I I , Pati ents hav i ng norma l vocal fol ds and , i n mos t cases , s l i ght adduction di s turbances : " functional voi ce di sor·ders "

I nt roduct ion , s peech therapi st ' s d i a gnos i s

more effec ti ve than the r·emova l I n 15 out of 64 pati ents no or-of a nodul e on a voca l fo l d , be- gani c d i s turbances of the voca l cause i n the l a t ter cas e the dy- fol ds or severe i nnerva t ion d i s-nami c cl os ure o f the gl ott i s ha rd ly turbances coul d be detected .

124

We were struck , howeve r , by the fact that i n the majori ty of the pat i en ts of Group I I the gl ott i s a t the dorsa l s i de , as vi s i b l e i n the mi rro r , was not compl etely cl osed duri ng phonati on . Compl ete c los u re coul d not be obs erved i n stroboscop i c exami nation e i ther .

Koi ke and Hi rano ( 1973 ) drew a ttention to the occurrence o f th i s i ncompl ete c los ure o f the carti l agenous pa rt of the gl ott i s ( the ch i nk ) , wri ti ng , " A phys i o­l o gi cal fact that has often been overl ooked or i gnored . . . Thi s fact has not drawn much attention so far , perhaps because of the di ffi ­cul ty i n i ts observat ion . "

Farnsworth ( 1940) as we l l as Schonharl ( 1960) obs erved th i s phenomenon i n normal s ubj ects wi th norma l soundi ng vo i ces .

�J i t h th i s i ncompl e te c l osure o f the g l otti s , the vocal i ntensi ty decreases and hoarsenes s occurs . Thi s decrease has a l s o been proved by experiments w i th the prepa red human l a rynx ( van den Berg and Tan , 1959 ; Tan , 1960 ) .

I t i s d i ffi cu l t to trace the caus e of an i ncomp l e te c l osure of the gl otti s . A s l i ghtly i m­perfect formati on of the l aryngea l s kel eton ( ca rti l ages , cri cothyro i d joi nt ) , o r o f the voca l fo l ds (e . g . hypop l a s i a or a su l cus gl otti di s )

a s wel l a s s l i ght i nne rva tion d i s ­turbances of the i nterna l l a ryngeal muscl es a l l are pos s i b l e .

A dyssynerg i a may express i tsel f i n an improper mutua l adjustment of the i nteraryteno i d , l a teral cri coarytenoi d , voca l i c , and cri co­thyro i d musc l es . These muscl es e ffectuate a proper adjustment of the voca l fo l ds as a counterbal a nce o f the expi ratory s ubgl otti c press ure . Moreover , a faul ty use of the l arynx , i ntenti onal or not , may a l so l ead to the habi t of i m­proper muscul a r adj ustment and a pers i s tent hoarse voi c e . Thi s characteri sti ca l ly occurs , when the speaker w i s hes to ach i e ve a ce rta i n voca l effect , as a rea l ­i za t i on of the persona l rol e he tri es to pl ay ( " voi ce i mage" , Cooper , 1973 ) .

Sedl a�kova ( 1 960 ) poi nted out the pos s i bi l i ty that stra i n i ng of the voi ce duri ng ch i l dhood may l ead to permanent changes of the m icro­structu re o f the voca l fol ds . I n l a ter years , thi s i s s upposed to l ead to an a trophi c aspect of the vocal fol ds and i ncompl ete c losure of the gl otti s .

I n cl i n ica l pract ice when pa­ti ents do not s how any organic di sturbances usua l ly consu l tat ion by a speech therapist wi l l take

125

Table 5- 1 2 . A classification of the regression lines from the 1 5 patients

of Patient Group I I , i . e . those having normal vocal folds and, in most

cases , slight adduction disturbances , the so-called functional voice

disorders . In the first part of this Table , a classification on the basis

of laryngoscopic findings is followed and in the second part a c lassi­

fication on the basis of the diagnosis of the speech therapist .

one or more regress ion l i nes a l l regres s i on l i nes outs i de reference areas wi thi n reference areas number

A . i nd i rect l a ryngoscopy of pa t .

no d i sturbances 2 hyperfunc tion on ventri c u l a r fol d l evel i ncompl e te g l otti s c l osure

0

7

B . speech therapi s t ' s di agnos i s

hypo k i neti c hyperki net i c dysk i net i c (mi xed hypo- and hyperk i neti c ) mutat i onal di s turbance psychogeni c dysphonia s pa s t i c dysphon i a dysphoni c fal setto

0 0 5

pl ace , e . g . for es tabl i s h i ng the phonatory pattern , and a l so for pl anni ng a proper voca l rehab i l i ­tati on programme .

The therapeuti c poss i b i l i t ies i n these pa ti ents wi th functiona l di s turbances a re l i mi ted to treat-

126

Patient No .

14 , 3 1

20 , 24 , 30 , 36 , 41 , 4 7 , 52

20 , 24 , 30 , 47 52 41 14 31 36

number of pat .

1 2

3

2 0

2

0 0

Pati ent No .

27 38 , 64

37 , 43, 59

37 38 , 59

43, 64 27

ment by vo i ce tra i n i n g . A compl ete recovery from the di s turbances i s i n mos t cases not pos s i b l e . The vo i ce l essons wi l l be ma i n l y a i med at an optimal use o f the l a rynx , wh i ch means t rai ni ng to acqu i re a more re l axed phona tory pattern .

Thi s can only resu l t i n i mprovement wi thi n the l i mi ts of the pos s i ­b i l i ty of functi onal adaptation o f the l a ryngea l s t ructures o f the pat i en t . After voi ce trai n i ng i t was often found that the pat i ent had fe�1er comp l a i nts of fat i gue a fter speak i ng for a l ong t ime and l es s di scomfort of the neck muscl es etc . Laryngoscopy , however , often shows that the s l i gh t adduction d i s turbances a re s ti l l present to an und i mi n i s hed degree . The res ul t of voi ce tra i n i ng , therefore , cannot be es tabl i shed by l aryngo­scopy al one.

A better voi ce wi l l be re l ated to a decreased open quoti ent , therefore the mean fl 0�1 va 1 ue at phonat ion may be expected to b ecome sma 1 1 er .

Tab l e 5-12 g i ves a s urvey of the reg ress ion l i nes of the patients in th i s group . I n ni ne out of fi fteen pat i ents we found one or more devi ant regress i on l i nes . The rema i ni ng six cases had no deviant regres s i on l i nes .

5 . 4 . 3 . 2 Di scus s i on on the experimental data

In Tab l e 5- 13 the va l ues for fl OI'I , pres sure , and effi ci ency at Im have been recorded . From an aerodynami c point of v i ew the

pat i ents show a fa i rl y uni form pattern , despi te d i fferences i n the speech therapi s t ' s di agnos i s . Moreover , i t i s notab l e that i n the ten pat i ents wi th i ncompl ete gl ott i s c l osure a devi ant h i gh fl ow was observed i n only two cases whereas s i x showed a subgl ottic press ure whi ch was too hi gh .

A s i gn i fi cant i mprovement i n E rel cou l d be ascertai ned i n four Pati ents , Nos . 20 , 30, 36 , and 4 7 .

Pati ent No . 2 0 h a d a rough and hoa rse voi ce , which was not un­common i n her rel ati ves . The pa­ti ent had been hoarse " from b i rth on " .

Even after treatment the qual i ty of the voi ce scarcely changed . There can be no doubt , however , that there was a s i gni fi cant im­provement i n the pat i ent , not only in vocal effi c i ency , but subjec­t i vely al so . She fe l t she wa s abl e to speak wi th l esser effort . Th i s mus t be exp la i ned i n terms o f an adaptation by the pati ent of her own phona tory pattern to the functional l imi tati ons of her l a ryngea l structures i n order to achi eve an optimal res ul t �1i th mi nima 1 effort .

The improvement o f the effi ci ency i n Patient No . 30 was al so remark-

127

abl e . Th i s improvement can only be as cribed to a change i n the phonatory pattern probably caused by psycho l ogi cal factors . The im­provement began after the pati ent l eft her nurses ' tra i n i ng s choo l . She had found th i s tra i n i ng too demandi ng and i t had a ffected her emoti onal ly . I n the fi rs t , a s wel l as i n the second meas uri ng seri es , her g lott i s appeared not to c l ose at the dorsa l s i de . Neverthel ess , at the second measurement , the effi c i ency of the vo i ce production had i ncreased and phonation de­manded much l es s effort .

I n the same way , i n the other cases in wh i ch an i mpro vement was found , i t cou l d a l s o be establ i s hed that the gl otti s cl osure had ha rd ly impro ved . The cl osure a t the dorsa l s i de was s ti l l i ncompl ete at the second meas uri ng series in mos t cases .

Sulcus glottidis

In Patient No . 36 , wi th appar­ently normal vocal fo l ds , but al so with an i ncomp l e te g l o tti s c l osure , the l a ryngo s copi c fi ndi ngs were i nterpreted fi na l ly as due to a congeni ta l hypopl a s i a of the l a rynx . Both vocal fo l ds sho�1ed l ongi tud i nal grooves and under­devel opment . A good chest vo i ce

128

qual i ty cou l d not be produce d . The speech therapi s t therefore ri ghtly described the voi ce of th i s pat i ent as " dysphoni c fa l s etto voi ce " .

After voi ce tra i n i n g , th i s pa­ti ent had c l early l earned to phonate at l ower s ubgl ott i c press ures , wh ich w a s the cause of a consi derab l e part of the im­pro vement achi eved i n the e ffi ­c i ency . The speak i ng voi ce p i tch l evel rema i ned h i gh for a ma l e voi ce , a t about F3 , ( 1 75 Hz ) . The sound qual i ty became somewhat l es s shri l l pos s i b l y because he had l ea rned to bri ng the ep i gl ott i s i n the di rection o f the a ryteno i ds at phonation .

Psychogenic dysph:mia

Two Pati ents from Group I I ( Nos . 14 and 2 7 ) deserve spec i a l atten­tion . They a re stri k i ng by thei r decrease of effi c i ency a s estab­l i shed in the s econd measurement . Pati ent No . 1 4 who cou l d only phonate in a squeaky voi ce in the fi rst meas uri ng seri es seems to have been ab l e to do th i s wi th more effi ci ency than was pos s i b l e for her i n the second measuring series where she was ab le to phonate norma l ly . In both pati ents there was q ues ti on of psychogeni c dysphon i a wi th , espec i a l l y i n

Table 5- 1 3 . Fifteen patients of Patient Group I I , i . e . those having

normal vocal folds and , i n mos t cases , s light adduction dis turbances .

(For legends see Table S-6 . )

Patient i nterval Im fl ow pres s . effi c . E rel /JErel therapy No . months dB ml /s kPa xl0- 5 dB dB

dev i an t 14 68 . 5 46 0 . 78 2 . 8 2 . 3

6 79 244 0 . 7 5 6 . 2 - 0 . 9 - 3 . 2 .. '

20 78 289 1 . 1 1 2 . 8 3 . 7 voi ce tra i n i ng 14 84 . 5 176 1 . 5 1 5 . 4 - 0 . 5 + 3 . 2*

24 78 . 5 333 1 . 1 2 2 . 7 - 4 . 2 vo i ce t ra i n i ng 1 3 7 3 197 0 . 81 1 . 8 - 2 . 5 + 1 . 7

30 77 399 0 . 88 2 . 1 - 4 . 5 vo i ce t ra i n i ng 14 79 286 0 . 81 4 . g - 1 . 9 + 2 . 6*

3 1 7 5 . 5 140 1 . 02 3 . 6 - 1 . 1 psychia try 14 78 191 1 4 . 8 - 1 . 4 - 0 . 3

36 76 . 5 281 1 . 6 1 . 4 5 . 7 voi ce t ra i n i ng 13 75 239 0 . 94 2 - 3 . 2 + 2 . 5*

4 1 77 444 1 . 02 1 . 6 5 . 5 vo i ce tra i n i ng 14 73 . 5 324 0 . 68 1 . 5 - 3 . 7 + 1 . 8

4 7 7 5 . 5 179 1 . 08 2 . 7 2 . 4 vo i ce tra i n i ng 7 74 172 0 . 63 3 . 4 - 0 . 4 + 2 *

52 75 299 0 . 88 1 . 7 - 3 . 9 voi ce tra i n i ng 1 1 75 . 5 302 0 . 7 2 . 4 - 2 . 8 + 1 . 1

non-deviant 27 78 . 5 86 0 . 83 14 . 3 3

13 76 . 5 155 1 . 05 4 - 1 . 3 - 4 . 3* 37 77 . 5 161 0 . 69 7 . 3 0 . 7 38 77 158 0 . 79 5 . 8 0 . 1 voi ce tra i n i ng

1 7 73 147 0 . 7 1 2 . 6 - 0 . 9 - 1 43 81 . 5 206 0 . 97 10 . 3 - 0 . 3 59 79 102 0 . 86 13 2 . 3 64 80 289 1 . 05 4 . 8 2 . 7 vo i ce tra i n i ng

3 76 . 5 265 0 . 9 2 . 7 - 3 - 0 . 3

129

No . 1 4 , a very pecul i ar aerodynami c spasti c dysphoni a . pattern , s ee Fi gure 5-4 . Th i s seems to be a di sorder o f

The psychogen i c dysphon i a i n Pati ent No. 1 4 appeared to be connected wi th severe domes ti c prob l ems . When these probl ems were so l ved , her voi ce recovered grad­ual l y . At the fi rst measuri ng seri es , the pati ent produced a s quea ky vo i ce , at the s econd meas uri ng seri es her voi ce d i d not sound dev i ant anymore .

I n the fi rst measur ing seri es of Pati ent No . 27 , she comp l a i ned that phonation was very ti ri n g . The voi ce often s a n k away and the pati ent became aphoni c . In the pas t she s uffered repeatedly from a psychogeni c aphoni a . I n these cases the voi ce returned sponta­neou s ly a fter some time . At the second mea s uri ng seri es , the pa­tient had no comp l a i nts about her voi ce and her phonati on was qu i te normal aga i n .

I n both pat i e nts , t h e aerodynami c patte rn became normal , which i s al so refl ected i n the experimental data e . g . by the better dynami c range i n Pati ent No . 14 .

Spas tic dysphonia

I n Pati ent No . 31 , we diagnosed

130

the vocal attack rather than of phonation as s uch . I t s eems to be characteri zed " by a stra i ned , crea k i ng , and choked voca l atta c k , a tense and squeezed voi ce sound that i s accompan ied by extreme tens i on of the enti re phonatory system" ( Berendes , 1938 ; Brodni tz , 1976 ) , o r o f the conti nu ity o f phonat ion , i n wh i ch " the breath stream i s at times bei ng l ocked by a st i ffly cl osed g lott i s " ( Dams te , 197 3 , 1978 ; Damste and Lerma n , 1975 ) .

Thi s i s born out by the exper i ­mental data that show that a fter the onset of phonat ion the effi ­ciency of the l arynx di ffers only l i tt l e from the reference va l ue .

Genei•a l discttssion

Roughly spea k i ng , there is a certai n s i mi l ari ty between the pati ents of Group I I (Tabl e 5 - 1 3 ) and the pati ents wi th voca l nodu l es from Group I ( Tabl e 5-7 ) . I n the l atter subgroup we often observed that duri ng phonat ion the g lotti s rema i ned open at the dorsa l part , even a fter s urgi cal removal o f the nodul es .

I n both groups the val ues of the subglotti c pressures at corre-

s pondi ng val ues of Im a re h i gh . The h i gh subgl otti c pressures o f the pa ti ents i n both groups , whi ch they obvious ly req ui re for pho­nati on , i ndi cate that these pa­ti ents effectuate the cl osure o f the gl ott i s wi th a s pec ia l effort. Therefore , a greater s ubgl otti c energy i s neces sary to keep the vocal fol ds v ibrati n g , and the g reater muscu l a r effort of the respi ra tory system and the l a rynx wi l l l ead to ti rednes s and compl ai nts .

1000

E( lo·•,

10 0

0

1

1---........- : I I

I I I I I

ell.a ) 7/ v--r. LV!

I I

flow.b � / ....-- I ;/ I

I d.eL ��-· I I 1--I ) I I I

: / / _;,! r4. ! Prof. v

I/ I �? � � p prus. b -

I I ' I I I

The fac t that at an i ncompl ete dynami c c l os ure of the gl otti s a nd

0 J 60 . /70 /80 90 100 I� I0: a normal fl ow va 1 ue a ra i sed sub- Figure 5-4.

! (dB)

0 1.

0 q(t/s)

.5

0 .2

0.1

0.05

1 0 p (kPa)

5

2

0.5

0.2

0.1

g l otti c pres sure may be found , Depiction of the regression lines

seems at fi rs t s i ght pa radoxi cal . for fl01• , pressure , and efficiency

A l ow va l ue for the s ubgl otti c from both measuring series in Fa-

p ressure mi ght have been expected . tient No . 1 4 , represented with the

It i s l i ke 1 y that a pati ent �Ji 1 1 corresponding reference regression

try to overcome hi s soft voi ce ( i n lines . The data of the first meas-

consequence of the i ncompl ete uring series have been marked with

c l os ure of the g lotti s ) by add i - a , those o f the second series with

ti onal contract i on of the adducti ng b. This patient had a psychogenic

muscl es . Some times thi s may be ob- voice disorder 1·Jith a high-pitched

served as a synergeti c adduction squeaky voice . A t the first meas-

of the ventri c u l a r fo l ds . Th i s can uring series , the voice was soft ,

be expl a i ned as a consequence of al though wi th a high efficiency ,

the greater mus cul a r effort of the which aopeared mainly to be the

patient try i ng to cl ose the resul t of the low flow values . At

gl ottis . The st l'i ated mus c l es per- the second series , the voice did

form extra 1�o rk and thus get sooner not sound deviant anymore , and the

ti red . Thi s l eads ul timately to potentiali ties of the voice appeared

a hyperfunctional use , because also to be normal , resulting in

practically normal aerodynamic data .

131

there i s rel ati ve ly exces s i ve tens i o n .

The ra i s ed s ubgl otti c pressure refl ects th i s extra effort of the res pi ratory musc l es as wel l as of the i ntri ns i c l a ryngeal muscl es , wh ich must have a h i gher ten s i on at a ra i sed s ubg l otti c pressure . In thi s way more i nternal tens i on i n the l a ryngeal musc l es themsel ves is produced by an i ncrease i n the l ongi tudi nal ten s i on ( cri cothyro i d musc l e ) , a n i nc rease i n the medi a l compress ion ( l a teral cri coarytenoid musc l es ) , and an i ncrease in the i nternal tens i on in the vocal fol d ( i nternal thyroarytenoi d mus cl e s ) .

A general l y ra i sed toni c i ty of the stri ated muscul ature , e . g . i n emotional ly tense persons , a l s o l eads t o a tense phonatory pattern , usua l l y as we l l observabl e i n thei r outward appearance .

The exces s ten s i on i n the vocal fol ds i nfl uences the fl exi b i l i ty of thei r movements , both i n the muscu l a r part as wel l as i n the superfi c i a l l ayer of ep i thel i a l ti s s ue ; beca use of th i s the di s ­pl acement ampl i tude of the vocal fo l ds wi l l be l ess duri ng a v i ­bration ci rcl e . One shoul d expect accordi ngly a l ower a i r fl ow rate to be mea s ured . Hm�ever , the quas i ­stati c i ncompl ete c los ure o f the gl ott i s prevents a decrease of the

132

fl ow due to reduced d i s pl a cement ampl i tudes . Because of the l esser di s p l a cement ampl i t udes of the vocal fol ds the a i r stream i s , a t the same ti me , l ess fu l l y modu­l a ted , produc i ng a softer bas i c sound .

The augmented subgl otti c pre s s ­ure , condi ti oned by the s ubjec t ' s effort to speak l oude r , contri butes further to e l evate the fl ow rate s , spi l l i ng subgl ottic power to the detriment of the effi c i ency of the vo i ce product i o n . Th i s vi c i ous ci rcl e has as res ul t that the exerted effort and the subject ' s fati gue i ncrease ou t of proporti on to the ach i e ved sound i nten s i ty .

I t s houl d a l so be taken i nto account that at i ncreas i ng sound i ntens i ty the adductory e ffect of the l aryngeal mus cl es has to be greater i n o rder to ach ieve an adequate cl os ure of the gl otti s . I n pati ents w ith s l i ght adduct ion d i sturbances the phenomena ob­servabl e duri ng soft phonat ion resemb l e those occurri ng i n normal subjects i n l oud phonat ion .

The cl i ni cal importance o f he l p i ng the pati ent es cape from the v i c i ous c i rc l e i n wh i c h addi ­ti onal phonatory effort yi e l ds d i mi ni sh i ng retu rns , cannot be stressed too strongl y .

A s a resul t of voi ce tra i ni ng

pati e nts may ach i eve the abi l i ty of phonati ng at l ower s ubgl otti c pressures and a l ess tense ad­justment of the voca l fol ds , per­mi tti ng a more fl exi b l e voca l fol d mobi l i ty . Accordi ngl y , too , the fu l l advantage of the Bernou l l i effect can be rea l i zed and the voca l fol ds wi l l cl ose the g l o tti s earl i er duri ng a vi bra ti on cycl e , caus i ng the open quoti ent to be sma l l er .

Conseq uently , then , t h e avera ge a i r f l ow rate wi l l decrease and the sharper wave shape of the g l ot t i s pu l ses wi l l enri ch the ha rmoni c structure of the bas i c sound . I n pa ti ents who phonate wi thout a compl ete g l o tt i s cl os ure i n the v ibrat ion cyc l e , a more re l a xed sty l e of phonation may c l ea r ly y i e l d a better modu l a ted a i r s tream . Whether th i s wi l l a l so decrease the ai r fl ow rate s i g­n i fi cantly or not wi l l depend on the s i ze of the res u l t i ng effective quas i - s tati c open ing of the gl otti s and the ul t imate he i ght of the sub­g l otti c pres sure .

The l ower subg l otti c pressure wi l l dimi n i s h the amount of wi l d a i r and the stream vel o c i ty , thus reduci ng the factors gi vi ng ra i se to turbul ence . Breath i ness wi l l be l ess conspi c i ous or even become i naudi b l e .

The amount of wi l d a i r i n certa i n cases , however , may be such that even after treatment the voi ce rema i ns breathy . Neverthel ess , by reducti on o f the effort needed for a certai n sound i ntens i ty , voi ce production even i n these cases wi l l be l ess ti ri n g , and the pati ent wi l l experi ence th i s sub­jecti vel y as an i mprovement . Ob­j ecti ve ly the i mprovement may be as certai ned i n a decreas e of the s ubg lotti c pressure val ues .

5 . 4 . 3 . 3 Conc l us i ons

Summari z i ng , we can make the fol l owi ng s ta tements wi th respect to the pati ents from Group I I : --

a . Even w i th an i ncomp l etely c l osed g l otti s phonations at

normal i ntens i ty l evel s can be produced w i thout h i gh a i r f l ow rates .

b . Psychogeni c i nfl uences on the voi ce production may sometimes

be revea l ed i n the aerodynami c pattern .

c . Voi ce tra i n i ng gene ra l ly l eads to improvement of the effi ­

c i ency . In these cases , both the functi onal poss i b i l i t ies and l i mi­tati ons of the phys i o l og i ca l structures a va i l ab l e for phonat i on and the aerodynami c factors i n phonat ion shoul d be taken i nto

133

account i n p l a nn i n g treatment and eva l uati ng as wel l as predi cti ng i ts res u l t .

5 . 4 . 4

5 . 4 . 4 . 1

GROUP I I I , Pati ents havi ng norma l vocal fol ds , but s ufferi ng from severe i nnervation d i s turbances

I ntroduction

La ry ngos copy of a normal l a rynx shows that each vocal fol d may a s s ume any o f a conti nuum of quas i ­stati c pos i ti ons , dependi ng on l aryngeal functi on : b reathi n g , phonation , wh i s peri n g , swa l l ow i n g , cough i ng , etc . Th i s i s rea l i zed as a res ul t of the mobi l i ty o f the a rytenoi ds and the contract i on under neuromotor control o f the mus c l e s i ns erted i nto the muscu l a r processes . For a di s cuss i on o f these pos i ti on s w e adopt the rough cl a s s i fi cat i on of Jes chek ( 19 5 3 , 1958) a n d Luchs i nger and Arnol d ( 1965 ) , see Fi gure 5- 5 .

Duri ng normal respi rati o n , both vocal fol ds are abducted and they occupy a pre l ateral pos i ti on . I n forced respi ra t i on they move i nto the l a teral pos i ti o n . These two pos i ti ons wi l l only sel dom be found as permanent pos i t i ons in cases of d i s turbed i nnervati o n .

134

The effect of para lys i s o f one or both l a ryngeal hal ves on vo i ce and respi rat ion depends o n the pos i t i on in wh i ch one or both vocal fol ds remai n fi xed .

The c l i ni ca l symptoms and s i gns resul ti ng from l a ryngeal para l ys i s are rel a ted to two factors : - -

a . Whether the pa ra lys i s i s u n i -l ateral or b i l ateral . ( For

b i l ateral paralys i s the wel l - known thumb rol e i s appl i cabl e : the wi de r the gl otti s open i ng at res p i rati on , the worse wi l l be the voi ce and vi ce vers a . )

b . The pos i ti on of the vocal fo l ds duri ng respi rati on and

duri ng phonat i o n .

When i n uni l ateral pa ra l ys i s the a ffected vocal fo l d stands sti l l i n medi an pos i tion , the vo i ce wi l l be about normal and respi rato ry di ffi cul ties wi l l not occur i n ord i nary c i rcums tances . Whi l e there wi l l be no respi ra tory probl ems i n case of uni l ateral para l ys i s wi th fi xation o f the a ffected fo l d i n paramedi an or i ntermedi an po­s i tion , i n the l atter case vo i ce producti on resu l ts i n a very breathy qua l i ty .

The vocal fo l d a t the non-para­l ysed s i de can be norma l l y adducted and someti mes appea rs to surpas s the median l i ne . Compensati on i s

usua l l y poss i b l e for a fi xed po­s i t i o n of one vocal fo l d up to the paramedi an pos i ti on . Such a com­pensat ion i s usual l y effectuated as a gradua l l y deve l op i ng adapt i ve process , i n whi ch the voi ce i s i n i ti a l ly hoars e , b ut gradua l ly becomes no rma 1 .

Compensation may occur as we l l by adductory movements i n the reg i o n of the ventri cul ar fo l ds , i nter al i a by contraction of the extri ns i c l a ryngea l mus cl es .

Severa l authors , Stern ( 1 929 ) , Dohne ( 1944 ) , and Arnol d ( 1948, 1955a , b , 1958 , 1959 ) , have pre­sented tab l es s ummari z i ng thei r observa t i ons of the typi cal course of changes of the voi ce in acute as wel l as gradual ly devel oped l a ryngea l pa ralys i s . Ho�1ever , i t seems to be very di ffi cul t to des c r i be genera l and cha racteri s t i c changes o f vocal qual i ti es i n con­necti on wi th va rious s tad ia of para lys i s .

Of practi ca l importance i s the fact that l a ry ngeal para lys i s i s a process i n 1�h i ch a stati ona ry cond i t ion devel opes only after a certa i n course of t ime . There i s no common consensus a s to the desi rabi l i ty of voi ce trai ni ng i n thes e cases .

Duri ng res t , a uni l a terai par­a lys i s causes no res pi ra tory d i ff i -

5 - LATERAL 4 - PRELATERAL

3 - I NTERMEOIAN 2 - PARAMEOIAN

1- MEDIAN

Figure 5- 5 .

Classi fication o f the positions

in which the vocal folds can be

seen a t laryngoscopic examinations .

cul ti es ; i n case of great effort though some dyspnoea may occur (Berendes , 1956 ) .

I n case of b i l ateral l aryngeal pa ra l ys i s wi th both vocal fo l ds fi xed i n median pos i t ion seve re res p i ratory d i ffi cu l t i es �1i 1 1 occu r , appeari ng as i nspi ratory s tri dor and dyspnoea , even at res t . I n s uch cases , there wi l l o f course b e no prob l em i n common phonati ng .

I n b i l ateral l a ryngeal para l ys i s wi th both vocal fol ds i n a fi xed i ntermedi a n pos i ti on the g lott i s i s ra ther wi de . However , there may

135

here be other res pi ratory probl ems of qu i te a di fferent nature and the pat i ent wi l l speak wi th a wh i s peri ng vo i ce , us i ng much a i r . The i nsp i rat ion of a i r i s not h i n­dered , but the rhythm of the res ­p i ration may be severely di sturbed and the pa ti ent often comp l a i nts of dyspnoea . Moreover , symptoms of hyperventi l at ion may appea r .

These res pi ratory probl ems need not be the resu l t of l ocal di ffi ­cul t i es i n pu lmonary venti l at i on , but can be re l a ted to changes i n the k i naesthet i c sys tem , i nfl u­encing the propri ocepti ve refl exes wh i ch regul ate the respi ratory rhythm ( Gou l d , 1 9 7 1 ) . The l ungs are defl ated too qu i ck ly as a resul t of the hi gh fl ow duri ng phonati o n , wh i ch is accompani ed 1�i th fa i rly hi gh al veol a r pres sures .

Duri ng phonat i on the vocal fol ds can move to the mi dl i ne pos i t ion as a res u l t of the Bernoul l i effect and the el asti c reco i l from a prev ious ly s i dewards di s pl acement produced by aerodynami c factors . The i nteracti ng effects of s ub­g l otti c pres sure , el ast i c i ty , and the Bernou l l i effect is maximal in voca l fol ds wh i ch a re not tensely s tretched . The degree of i nternal tens i o n of the vocal

1 36

fo l ds , therefore , i s a l s o o f i m­portance . Th i s depends ma i n ly on the acti v i ty of the cri cothyro i d musc l e .

I n Group I I I , compri s i n g s even pat i ents a cross section of the typi cal c l i ni ca l aspects of l aryngeal pa ra l ys i s i s pre sent , see Tab l e 5- 1 4 . The s ubgroup u n i ­l a tera l para l ys i s cons i sts o f three , the o n e wi th b i l atera l pa ra lys i s , of four pati ents . I n both s ubgroups , there i s one s i ngl e pa t i ent whose regress i on l i nes a l l l i e wi th i n the reference a reas . Fi gure 5-6 g i ves a survey of the fi ndi ngs at l a ryngoscopy .

5 . 4 . 4 . 2 D i s cuss i on o n the experi mental data

Uni ZateroZ lm•yngea Z pm'aZysis

The resu l ts of the measuri ng seri es from the three pa ti ents are summari zed i n Tabl e 5 - 1 5 .

Pati ent No . 2 , a woman o f 5 5 yea rs , hav i ng a para lys i s of the l eft s i de of the l a rynx , of unknown cause . At the t ime of the fi rst measuri ng series the paral ­ys i s had l as ted 1 B yea rs .

Al though the ri ght vocal fo l d a t phonation surpassed the med i a n

Table 5- 1 4 . A classification of the regression lines from the seven pa­

tients of Patient Group I I I , in whom a dis turbance of the mobility of

one or both laryngeal halves could be estab l ished.

i nnervation d i sturbance one or more regress i on l i nes al l regress ion 1 i nes outs i de reference a reas w i t h i n reference a reas number of pat .

u n i l a tera l 2 b i l a teral 3

l i ne , the compensation was not a dequate . The vo i ce was soft and speaki ng was ti ri ng . About two years l ater, at the second meas­uri ng seri es , a s l i ght deteri o­rat i on appeared to have devel oped . Th i s co rres ponded wi th the subjec­ti ve experi ence of the pati ent . She compl a i ned more than before about di ffi cul ty i n b reathi ng and dys pnoea , wh i ch corresponded �1e l l w i th the hi gher a i r fl ow rate a t Im . T h e re l ati ve effi c iency was very l ow ( -9 . 4 dB ) .

Pati ent No . 6 was a woman of 64 yea rs wi th a pa ralys i s of the l eft s i de of the l a rynx caused by me­tastases of brea st ca ncer .

There were few s i gns of compen­sati on by the ri ght s i d e , poss i b l y because the pa ra l ys i s had only l as ted a fortni ght at the time of meas uri ng . The vo i ce was soft and

Pati ent number Pati ent No . of pat . No .

2 , 6 26 1 ' 9 , 56 23

phonation demanded much effort . The eff i c i ency l i ne was devi ant , because fl ow and pressure ran j u s t a t the border of t h e rel evant reference areas . Because of the death of the patient , a second measuring seri es d i d not take pl ace .

Pati ent No . 26 was a woman of 32 yea rs wi th a pa ra l ys i s of the l eft s i de of the l arynx , whi ch at the t ime o f the fi rst measuri ng series had l asted 5 years .

The a ffection started duri ng a vi ra l i nfection as a b i l atera l pa ra l ysi s wi th both vocal fol ds in med i an to paramed i an pos i t i o n . Later , the mob i l i ty of the ri ght s i de of the l a rynx returned , l eadi ng to the d i sappearance of the respi ra tory di fficul ties . At the t ime of the fi rst measuri ng series a good compensati on by the

137

Uni l a teral Paralys i s B i l a teral Para l y s i s

dur i ng breathing during phonation during breathing during phona tion

max. abduction max. adduction max . abduction 111a x . adduction

Figure 5-6 . A survey of the laryngoscopic findings during respi ration

and phonation in seven patients with severe innervation disturbances of

the larynx. ( Shading : ventricular folds )

1 38

Table 5- 1 5 . Three patients, from Group III, with an uni latera l

innervation dis turbance .

(For legends see Table 5-6 . )

Patient i nterval I fl ow m press . effi e . Erel IIErel No . months dB m l / s kPa x l0-5 dB dB

devi a nt 2 69 . 5 432 0 . 98 0 . 3 - 8

27 7 1 681 0 . 97

6 70 293 0 . 67

non-deviant 26 80 212 1 . 01

14 79 172 1 . 22

r i gh t s i de exi s ted , s i nce the r i ght voca l fol d s u rpassed the med ian l i ne at phonat ion . The voi ce was practi cal ly normal , th i s pa t i ent partook of ama teur act i n g in a cl ub �1i thout havi ng any probl ems wi th her vo i ce . I n aerodynami c res pects , the val ues for press u re were on the h i gh s i de , howeve r sti l l wi th i n the l i mi ts of the refe rence area . The regres s i on l i nes for flDI'I and effi c i ency d i ffered only ve ry l i ttl e from the reference regress ion l i nes .

0 . 3 - 9 . 4 - 1 . 4 0 . 7 - 4 . 5

6 . 7 - 1 . 2 5 . 4 - 1 . 5 - 0 . 3

di scomfort . Th i s corresponded wel l wi th the fact that a deviati ng regress i on l i ne for subgl ott i c pres s u re was measured . For the usual sound i ntens i t i es of ordi nary conve rsati on , the l arynx was wel l compensate d , but at l ouder speech a deviant aerodynami c pattern a ppea red rather soon , because the a i r fl ow rate and the s ubgl otti c pressure i nc reased too q u i c k l y ( l a rge va l ues o f t h e regress i on coeffi c i ent b ) .

At the second mea s u r i ng series , about one yea r l ater , the effi ­c i e ncy at the mi ddl e of the dynami c range had rema i ned nea r ly at the s ame value as i n the fi rst meas ­ur i ng . The pat i ent to l d us , though , that phonation caused her more

Bilateral Za11Jngeal para lysis

The res u l ts concerni ng a l l four pat i e nts from th is s ubgroup , have been represented i n Tabl e 5- 16 .

Three pa ti ents showed devi ant regress i on l i nes in the fi rst

139

meas uring seri es . I n connecti on wi th the exi st i ng di ffi cul ty i n breathi ng , i n three pati ents i t was necessary to wi den the g l otti s by surgi cal i nterventi on.

Pati ent No . 1 v1as a woman of 49 years o l d , sufferi ng from a b i ­l a tera l para lys i s after thyro i d ­ectomy , whi ch a t the time of the fi rst measuri ng seri es had l as ted for two years .

The pati ent had a rough and hoarse voi ce , and , at respi rat i o n , the gl ott i s was not wi de enough .

She comp l a i ned about dys pnoea , wh i ch she experi enced at the l east effort. Her l eft vocal fo l d stood st i l l in a pa ramedian pos i t ion w i th l i tt l e pos s i bi l i ty of movement towards the medi an l i ne . At pho­nati on the l eft vocal fo l d touched the ri ght vocal fol d wh i ch stood st i l l in paramedian pos i t i o n . At stroboscop i c exami nati on an i r­regu l a r vibrati on pattern was ob­served , with a short cl osed phase .

The effi c i ency , at -9 . 1 dB , �1as very l ow . Though the gl otti s v1a s practi ca l ly cont i nua l ly open , the a i r fl m� rate v1as not dev i an t . The subgl otti c pressure was much h i gher than normal .

I n th i s pati ent the respi ratory probl ems made a surgical wi den i n g of the gl ott i s neces sary . However ,

140

the pat i ent d i ed soon a fter the fi rs t measuri ng seri es because o f devel op i ng metastases of the ma l i gnant thyro i d neopl asm.

Pati ent No . 9 was a woman of 44 years w i th a b i l ateral l aryngea l para l ys i s whi ch had devel oped a fter a thyro i dectomy one year prev ious to the fi rst measuri ng seri es . At fi rst both vocal fol ds s tood in pract i cal ly medi an pos i ti on ( posti cus pa ra lys i s ) wi th s evere respi ration d i fficu l t ies , neces s i ­tat i ng tracheotomy . When de­canu l a ti on was pos s i b l e , the voca l fo l ds st i l l appea red to remai n i n pa ramedian pos i t ion . By voi ce tra i n i n g , the pat i ent recovered her vo i c e , but it remai ned soft and breathy . At phonation , the vocal fol ds made contact wi th each other for about hal f the l ength of the gl otti s , as a resul t of the Bernoul l i effect and the e l a s t i c recoi l .

Together with the i mprovement of the vo i ce , the dyspnoea i n­creased and an arytenoi dectomy w i t h partia l chordectomy wa s i nd i cated . The f irst measuri ng seri es , im­mediately previ ous to the ary­tenoi dectomy , had been performed when the vo i ce wa s s l i ghtly hoars e . The effi c i ency was , desp i te her comparati vely optimal vocal paten-

Table 5- 16 . Four patients, fr>om Gr>oup III, with bilateral innervation

distur>bance .

(For legends see Table 5-6 . )

Pat i ent i nterval Im fl ow pres s . effi e . Erel 6Erel therapy

No . months dB ml /s kPa x 10-S dB dB

devi ant 1 69 325 1 . 59 0 . 2 - 9 . 1

9 67 . 5 355 0 . 8 7 0 . 3 - 7 . 3 a rytenoi dect . + 24 5 1 . 5 688 0 . 54 <0 . 01 - 14 - 6 . 7* part . chordect .

56 79 1 039 0 . 88 1 . 3 - 7 . 9 arytenoi dect. + 15 77 . 5 406 1 . 55 1 . 3 - 6 .8 + 1 . 1 part . chordect .

( vert i co- l a t . d i s pl acement)

non-deviant 23 76 2 1 7 0 . 92 2 . 9 - 2 . 3 arytenoi dect . +

12 69 . 5 832 1 . 26 0 . 1 - 1 1 .9 - 9 . 6* part . cho rdect .

t i a l i ti es at tha t moment , s t i l l l ow as a resul t o f the h i g h va l ues for fl ow and s ubgl ott i c pressure . The l ow val ue of Im i nd i cates that the dynami c vocal potenti a l i t i es were sma l l .

A fter the operati on the pa ti ent cou l d only whi sper . On the ri ght s i de a sma l l ventral pa rt of the voca l fo l d rema i ned , the l eft voca l fol d had an atro ph i c appearance and stood s t i l l in i ntermedi a n pos i t i o n . Consequen t l y , a w i de gl ott is had been achi eved , and brea th i ng di fficul t i es di sappeared .

About a yea r after the opera t i on the second measuri ng seri es was ca rri ed out . The effi c i ency of her lvh i s pered voi ce had become very

l ow : -14 dB and for Im a va l ue of on ly 5 1 . 5 dB was obtai ned . The dynami c range of course l i es much l ower than for a norma l vo i ce . The pa t i ent used much a i r for wh i s­peri ng at comparati vely h i gh va l ues for s ubgl ott ic pressure .

( I n the eval uation o f effi ci ency val ues one needs to take i nto account that the reference re­gres s i on l i nes have been extra­pol ated to 5 1 . 5 dB . Real reference val ues for whi speri ng i n norma l s ubj ects had not been ascerta i ned ) . The pa t i ent coul d not produce a sati s factory vocal i ntens i ty even if s he tri ed hard . She was severel y handi capped i n her soc i a l rel ati ons because of her l i mi ted pos s i -

1 4 1

b i l i t i es of speech communicati on .

Patient No . 56 was a woman of 47 years wi th a bi l atera l l a ryngeal para l ys i s after thyroi dectomy , whi ch had taken pl ace one year prev i ous to the fi rst measuri ng seri es .

Both vocal fol ds s tood s ti l l between paramedi an and i ntermedi an pos i t i o n . Desp i te the fa i rl y wi de gl otti s open i n g , the pat i ent s uf­fered from a severe dys pnoea . l-ihen spea k i ng her voi ce was very breathy , and she l o st much a i r . The pat i ent cou l d only s peak i n short phrases , her speak i ng rate was by nature very hi gh and , there­fore , i n spea k i ng she often became dyspnoei c . The respi ra tory di ffi ­cul ti es were primari l y caused by the h i gh a i r fl ow rates at pho­nation , ma k i ng necessary a q u i c k i nspi rat ion i n the mi ddl e of a sentence . The pat i e n t , however , was not abl e t o wi den her gl otti s suffi c i ently during q u i c k i nsp i ­ra tion to rep l e n i s h the a i r s uppl y .

O n the l eft s i de , a n a ryteno i d­ectomy and part i a l chordectomy were performed . The res t of the left true vocal fo l d was pa rti a l ly detached and di verted i n cran i a­l a teral di recti o n , then rea ttached c l ose to the l eft ventri c u l a r fol d i n a va riant of Langn i ckel ' s

142

operation ( Langni ckel and Koburg , 1970 , 1972a , b and Langn i ckel , 1976 ) .

The pat i ent soon devel oped a fa i rly normal vo i ce , s i nce a gl otti s was formed between the ri ght ventr i cu l ar fo l d and the fol d o f t i s s ue c reated o n the l eft s i de , thus enabl i ng vo i ce producti on . Before the operation the effi c i ency was l ow , ma i nly due to the h i gh a i r fl ow rates .

At the second measuri ng seri es , after the opera t i on , the fl ow val ues duri ng phonation appeared to have decreas ed consi derab ly . Though the s ubgl ottic pres sure was much h i gher , the effi c i ency of the l a rynx had been ra i sed somewhat , see Fi gure 5-7 .

Pos t-operati ve ly , the pat i ent was very satisfied about the im­provement of her voi ce and her respi ratory poss i b i l i t i es .

Pati ent No . 23 was a man of 52 years wi th a b i l ateral l a ryngea l para lys i s , pos s i b l y caused by a vi ra l i nfection about two years previ ous to our fi rs t measuri ng seri es .

Because both voca l fo l ds were fi xed pract i cal ly i n med ian po­s i t i o n , the vo i ce sounded nea rly norma l . At phona t i on , the s l ackened vocal fo l ds ti ghtened , probab ly

by the action of the cri cothyro i d 100 0 t i:P. I =-c1 .0 q(lfs)

0.5 mus c l e , moreover there was some E< 1o·•1 I I

- �� a dduction o f the l eft vocal fo l d , wh i ch enab led h i m to c l ose the g l ott i s properly at phonat ion . As far as regress i on l i nes for fl ow , pressure , and effi ci ency are con­cerned , these appeared not to be devi ant in the fi rst measuri ng seri es .

Because of th i s confi gurat ion of the g lotti s , the pa t i ent s u f­fered from s evere respi ra tory troub l e even at the s l i ghtest effort . I n q u i et breath i n g , the vocal fo l ds moved apart by the a i r s tream . Surg i ca l wi den i ng of the gl otti s was i nd i ca ted .

After the arytenoi dectomy and par ti a l chordectomy , there were no respi ra tory di ffi c u l t i es any­more . By voice tra i n i n g ( push ing excerci ses ) the pat i ent recovered a hoarse voi ce . A gl otti s was formed between a hypertroph i c ventri cul ar fo l d at t h e s i de of the arytenoi dectomy and the oppo­s i te true vocal fo l d . The aero­dynami c data shm�ed that vo i ce production cos t mat·e energy . The effi c i ency of the l a rynx had de­c reased consi derab l y ; the fl ow and the subgl otti c pressure va l ues had much i ncreased .

The res u l ts of surgi cal wi den i ng

10 0

0

1

0 .1

flow b

� 1--

I7 /� 1/•'•"·d /V; 17

I I I --- / I / I I hret I I I / I I I

!-7 I •7 •"·· w Pr� v

_./ v v I

: I I ' I '

60 70 //80 90 100

0.2

0.1

0.05

1 0 p (kPal

5

0.5

0.2

0.1 I ( dB)

Figure 5-7 .

Depiction of the regression lines

for flow , pressure , and efficiency

from both measuring series in Pa­

tient No. 56 , represented with the

corresponding reference regression

lines . The data of the first meas-

uring series have been marked lo/i th

a , those of the second series with

b . After an unilateral arytenoid­

ectomy and a partial chordectomy

with crania- lateral displacement

of the res t of the vocal fold , the

preSSIJ re values aooear to lie much

h ighe r , lo/hereas the air consumption

has decr eased considerably , lo/ith

no s ignificant change in the

ef ficiency of voice production .

143

of the gl ottis vari ed wi th respect to the l aryngeal effi c i encies . I n the Pati ents Nos . 9 and 23 , the effi c i ency decreased very much , i n Patient No . 56 , thi s was not the cas e . It seems l i kely that the choi ce of the s urgi cal procedure i s an essent i a l fac tor i n a proper ma i n tenance of the vocal function .

General discussion

Much i nformati on on a i r fl ow rate i n the phonation of pati ents wi th l a ryngeal para l y s i s may be found in the l i terature. Dehne ' s s tudy ( 1944 ) on a i r consumption i n u n i ­l a teral l a ryngeal paralys i s pro­vi ded the mos t extens i ve data on the s ubject . He found that the a i r cons umption i n phona ti on i n h i s pati ents was much hi gher than i n normal s ubjects . Dehne recorded va l ues for a i r cons umpti on in cases of severe hoarsenes s wh i ch were 4 to 5 t imes as h i gh as norma l . Even i n case of sl i ght hoarseness , the val ues appea red twi ce as h i gh .

Many other authors , Arnol d ( 1955a , b ) , I s s h i ki and von Leden ( 1964 ) , Yana gi hara and von Leden ( 1967 ) , Hi rano , Koi ke , and von Leden ( 1968 } , Ko i ke and H i rano ( 1968 ) , von Leden ( 1968) , Iwa ta and von Leden ( 19 70a , b ) , · Iwata , von Lede n , and W i l l i ams ( 19 72 } ,

144

and Hi ppel and Mrowi nsk i ( 1978 ) , reported h i gh a i r fl ow rates i n pati ents w ith l a ryngeal para l ys i s .

The h i ghes t val ues have been found in pati ents wi th uni l ateral pa ralys i s in wh i ch the pa ralysed vocal fol d s tood i n i ntermed i an pos i ti on . Lower va l ues were measured in uni l ateral para lys i s wi th the vocal fol d i n paramedi a n o r medi a n pos i ti on a n d i n cases s u fferi ng from b i l a teral abducti on paralys i s .

Leanderson and Grape ( 19 6 7 ) s i mul taneous l y measured the s ub­gl otti c pressure and the a i r fl ow rate i n one pati ent after chordectomy had been performed and voi ce l essons had been g i ve n . The subg l o tt i c pressure was meas u red di rect l y by puncturi ng the s ub­g lott ic space with a needl e . They found , compari ng the resu l ts w i t h those obtai ned i n exami n i ng a normal s ubjec t , a s l i ghtly ra i s ed ai r fl ow rate together wi th , what they cal l ed , a norma l press ure ( 10 . 6 cmH2D } duri ng soft phonat i o n . A t l o uder pho nat ion ( a ra i se o f 1 0 dB ) they coul d not establ i s h any i ncrease i n pressure va l ues , whereas a doub l e fl ow val ue was meas ured .

Contra ry to the genera l l y accepted i dea that i n l aryngeal paralys i s the s ubgl otti c pressure

has decreased ( Jes chek , 196 1 ; Luchsi nger and Arnol d , 1965) i t appea rs from our data that con­s i derably hi gher s ubgl otti c pressures than those observed i n normal s ubjects can be measured in pat i ents wi th l a ryngeal pa ra l ­y s i s and a deviant vo i ce qual i ty . There certai n ly i s no quest ion o f l owered s ubgl otti c press ures , despi te the fact that the gl otti s remai ns open at phonation . Dohne ( 1944 ) al ready s ugges ted that th i s mi ght pos s i bly be the cas e , but experi menta l proof was not reported in the l i terature .

The h i gh va l ues for the s ub­g l otti c pressure as found i n Pa­ti ent No . 9 are , of course , pa rtly caused by the press ure Pr needed to overcome the v i s cous res i s tance . Th i s pat i ent used a i r fl ow ra tes up to 1200 ml / s . The pres sure Pr wi l l then reach a val ue of 0 . 27 kPa ( 2 . 7 cmH20 ) , wi th a norma l va l ue for the v i s cous res i s tance . Eve n , when taken th i s va l ue i nto accoun t , the es tab l i s hed subg l otti c pressure va l ues are hi gh . Moreover , these val ues a re i n agreement wi th the va l ues found in a di rect measurement by Leanderson and Grape ( 196 7 ) .

A hi gh fl m� may be the resu l t of a l owered tens i on of the a f­fected vocal fol ds as we l l as of

a h i gher subgl otti c pressure . At hi gher a i r fl ow rates , the Bernou l l i effect has a greater i nfl uence on the medi a l ly di rected movement of the voca l fo l ds , wh i ch enabl es the gl ottis to c l ose pa rtly duri ng phonati o n . E ven i f both vocal fol ds are fi xed in paramedian pos i ti on th i s may happen { Pat ient No . 9 , before operat i on ) .

For practi cal and effect i ve s peech communi cati on a certa i n sound i ntens i ty l evel has to be pos s i b l e . Pati ents wi th l aryngea l pa ra l ys i s often appear ab le to produce th i s neces sary i ntens i ty l evel , but because of the l ower effi c i ency of the l a rynx , they have to exert greater effort . I f a h i gh fl ow has to be used the l oss of a i r shortens the phonation t ime and only short sentences a re pos s i b l e . Thi s l eads a l s o to very q u i c k i nsp i rati on , which poss ib ly l eads to i nspi ratory stri dor and breathi ng d i fficul t ies ( Pati ent No . 56 , before operation ) .

Subgl ottic pres sures which are only a l i tt le h i gher than the average va l ue i n normal subj ects were recorded i n pa ti ents i n whom dynam i c c l os ure of the gl otti s was poss i b l e . By stroboscopi c obser­va tion , the obvi ously s ti l l fl exi b l e vocal fol ds cou l d be seen touch i n g each other. Th i s was the

145

case i n Pati ent No . 23 duri ng the fi rst measuri ng seri es and i n Pa­ti ent No . 26 dur i ng both meas uri ng seri es . In these two pat i ents , the voi ce was practi cal ly norma l , the fl ow va l ues were not devi ant e i ther , and there was a compl ete dynami c c los ure of the gl otti s .

I t may be concl uded that there i s l i ttl e di fference between b i ­l ateral ( N o . 2 3 ) or uni l a te ral { No . 26 ) l a ry ngea l paralys i s as far as phonation is concerned , provi ded dynamic cl osure o f the gl otti s is poss i b l e . In Pati ent No . 6, dynami c cl osure was im­pos s i b l e at l ow i ntens i ties . The voi ce , there fore , sounded breathy , but appa rently a s l i ght i ncrease in the fl ow was suffi c i ent to achi eve c l os ure of the gl otti s due to the Bernoul l i effec t . An i nc rease in ext ra l aryngeal and i ntral a ryngea l mus cul ar effort for a better gl otti s cl osure , wh i c h wou l d have resu l ted i n a h i gher subgl ott i c pres sure , is thus not necessary .

5 . 4 . 4 . 3 Conc l u s i ons

Summari z i ng , we may draw the fol l owi ng concl u s i ons based on the pat1 ents from Group I I I : - -

a . I n cases o f l a ryngeal para l ­ys i s the aerodynami c data

146

depend on the rema i n i ng pos s i ­bi l i ti es of ach i evi ng dynami c cl osure of the gl otti s . The fl exibi l i ty of the vocal fol ds is often deci s i ve for the pos s i ­bi l i ty of dynami c gl ottis c l os ure , i n wh i ch case the effi c i ency o f the voi ce producti on may b e practi cal l y normal .

b . The resu l t of a s urg i ca l wi deni ng of the gl ott i s o n

the vo i ce production s eems to depend on the sel ected surgical procedure . The recovery of the respi ratory poss i b i l i t i es wi th maxi mum conservation of vo i ce functi o n , i ntended by the surgi cal method a s s ugges ted by Langn i ckel , needs to be studi ed and di s cussed .

Chapter 6 Investigation conducted with trained singers

6. 1 Introduction

I n the l a s t few yea rs there has been a growi ng i nteres t in i nves­t i gation of the tra i ned s i ng i ng voi ce . The maj ori ty of s tudies concern the acous ti c aspect of the produced vocal sound . In par­t i c u l a r , much attent ion has been pa i d to the so-cal l ed " s i ng i ng formant" , and ti mbre and perceptual di fferences between the vari ous regi s ters {Large , 1968, 1969 , 1973a , b ; La rge and S h i p p , 1969 ; Sundberg , 1970 , 197 3 , 19 75 , 197 7 ; Col ton , 1972 , 1973a , b ; Hol l i en , 1972 , 1974 ; La rge , Iwata , and von Leden , 1970 ; Seymour , 1972a , b , c ; Col ton and Hol l i e n , 1973a , b ; C l evel and , 1977 ; Murry , S i ngh , and Sa rgent , 1977 ) .

Coveri ng of the s i ngi ng vo i ce has been descr ibed by van Dei nse ( 1973 ) , van De i ns e , Frateur , and Kei zer ( 1974 ) , and Bunch ( 1976 ) .

H i rano , Ko i ke , and Joyner ( 1969 ) , Vennard , H i rano , Ohal a , and Fr i tzel l ( 1970a , b, 197 1a , b) re­ported on extens i ve e l ectromyo­g raphi c studi es of i ntri ns i c l aryngea l mus c l es i n normal s ub­j ects , i nter a l ios s i ngers . S urvey a rt i c l es on th i s s ubject have been publ i s hed i n 1969 and 1970 by H i rano , Venna rd , and Ohal a , wh i l e H i rano i n 1974 made a n i ns truct ive

fi l m on the subjec t . I n 1968, Proctor gave a survey

of the phys iol ogica l bas i s of s i ng i ng vo i ce tra i n i n g . Besi des , va r ious books on the s i ng i ng vo i ce for use i n s i ng i ng i ns truction have been pub l i s hed (Venna rd , 196 7 ; M i l l er , 197 7 ; Husl er and Rodd­Ma rl i ng , 197 8 ; Sei dner and Wendl e r , 1978 ) .

I nvesti gations concern i n g aero­dynami c aspects of the s i ng i ng voi ce have rema i ned l i mi ted . Measurements o f the a i r fl ow rate at the onset of the voi ce have been performed by Venna rd and I s s h i k i ( 1964 ) , Ko i ke , Hi rano , and von Leden ( 1967 ) , Werner- Kukuk and von Leden ( 1970) , Murry and Schmi tke ( 1975 ) , Leeper ( 1976 ) , and for vari ous voi ce reg i s ters : McG l one ( 1967 , 1970 ) , Large , Iwata , and von Leden ( 1970 ) , and Large and Iwata ( 1971 ) .

S i mul taneous measuri ng of fl ow , di rectl y meas ured s ubgl ott i c pres s ure , and sound i ntens i ty , f rom �1h i ch the eff i c i ency cou l d be ca l cul ated was performed by Rubi n , LeCove r , and Venna rd ( 1967 ) . They rema rked though that " the va r i­abi l i ty of the findi ngs among the s ubjects and wi th i n a s i ngl e sub ­j ect precl uded quanti tati ve ana lys i s " .

Bouhuys , Procto r , and Mead ( 1966 )

147

Table 6- 1 . A survey of the subjects

Subj ect voi ce nationa l i ty No . cl ass i fi cation

3 bari tone dutch 13 tenor canadi an

17 bari tone dutch

62 tenor amer ican

63 bass german

reg i s te red fl ow and i ndi rectly measured subgl otti c pressure i n s i ng i n g . Thei r i nvesti ga t i on was prima ri ly a imed at the quest ion of how the res pi ratory muscu l a ture provi des the energy for phonati on . Bouhuys , Mead , Proctor et a l . ( 1968 ) reported on the effi c i ency of one trai ned s i ngi ng vo i ce .

I n 6 . 2 , we des cri be our i nves ­t i gat ions wi th fi ve s i ngers , amongst whom two s i ng i ng teachers .

I n 6 . 3 , some q ual i tati ve aspects of the produced vocal sound are dea l t wi th . I n th i s connecti on we menti on the occurrence of the s ingi ng forman t and the v ibrato , as characteri s ti cs of a wel l ­tra i ned s i ngi ng vo i ce . Further , a spec ia l resonance phenomenon i s di scussed .

148

with a trained singing voice .

tra i ned amateur s i nger profess i onal s i nger , teacher of s i ng i ng advanced student i n s i ng i ng profess i onal s i nger, teacher of s i ng i ng tra i ned s i nger , med i ca l speech therapi s t

The i nstances of phonation pro­duced by the subjects i n thi s part of our i nvesti gat ion and di scussed i n th i s Chapter may al l be s a i d to b e model s of what tra i ned s i ngers at the bes t of thei r abi l i ty may hope to achi eve . There­fore , tones that 1�ou l d not be acceptab l e to the performer h i msel f in s i ng i n g a concert , were rej ected on h i s j udgement as qual i tati ve ly bad or not q u i te s u ffi c i ent .

I n produci ng the sung tones , the si ngers were somewhat h i ndered by the arti t i c i a l el ongation of the voca l tract and the fi xed shape of the mouth , constra i ned by the mouthpi ece , whi ch someti mes i ndeed was experi enced as uncomfortabl e . The use o f a mas k wi th pneumo­tachograph , as empl oyed by Rubi n ,

Table 6-2 . Table of data for flow , pressure , and efficiency derived from

the regression li nes from the five subjects with a trained singing voice .

( For legends see Table 5-S . ) In Subj ect No . 1 3 , the interval between the

measurements was one day , in Subj ect No . 62 , with three measurements ,

two days and three days .

Subj ect i nterval Im fl ow press . effi c . Erel t>Erel No . months dB ml /s kPa

3 81 237 0 . 66 1 1 82 2 1 7 0 . 84

1 3 87 312 1 . 62 0 83 . 5 259 1 . 48

1 7 82 . 5 253 1 . 1 1 81 208 1 . 02

62 84 . 5 241 1 . 33 0 83 . 5 259 1 . 36 0 86 . 5 245 2 . 02

63 7 7 . 5 195 0 . 49

LeCover , and Vennard ( 1967 ) ap­pea red to provi de l i tt l e subjecti ve i mprovement . In 6 . 2 , the i nfl uence of the e longated voca l tract wi l l be further di scussed .

Despi te the menti oned handi caps we a re convi nced tha t the re­g res s i on l i nes obta i ned are suf­f i c i ently rel i ab l e to a l l ow to draw proper quanti tati ve conc l u s i ons .

I n one subj ect , some vari ants of the s i ng i ng vo i ce producti on trai ni ng techni ques have been i nvesti gated . The res u l t wi l l be di s cussed in 6 . 4 ; 6 . 5 g i ves conc l us i ons .

6.2

x10-5 dB dB

1 1 . 6 1 2 . 6 14 . 2 8 . 5 9 . 2 8 . 6

1 2 . 7 9 . 2

1 3 . 0 8 . 5

0 . 5 0 . 2 - 0 . 3

- 2 . 4 - 2 . 4 0 . 0 - 1 . 5 - 0 . 8 + 0 . 7 - 1 . 3 - 2 . 1 - 0 . 8 - 2 . 5 - 0 . 4

1 . 4

Flow, subglottic pressure,

and efficiency of phonation

in trained singers

Among the normal s ubjects i nves­ti gated and reported on in Chapter 4, there were fi ve ma l e subj ects who had had a formal s i ng ing trai ni ng or were advanced s tudents in s i ngi ng , see Tabl e 6- 1 . A t9tal of ten measuri ng series were carri ed out i n these fi ve s i ngers , see Tab l e 6 - 2 .

I n Subjects No . 3 a n d No . 1 7 , pi tches were chosen accord i ng to the system of pre- sel ected fre­quenc i es , i n the other s i ngers we took pi tches i n steps of a q uarter

149

I_,/-../' ( """ii?.R?, 62c 13a

[ � r:= q,.,

\ ----I--1=7

-d � ------� ""� k � 62· � 13· \ v

r-......

/

A � v./ v

-d 1 .0

q (l/s) 0.5

0.2

0.1

0.05

� 1 � 0

p (kPol 5 rJ 2

0.5

0.2

60 70 80 90 100 !(dB)

0.1

/ / 7 / [7 � 82c

I 13� !r 7� 62.

62•

rl v

r 1/:,i 17� W' 1/� W7

1 000

E( 10"5)

� �1 00

1 0

1

60 70 80 90 100 °1 HdBl

Figure 6- 1 . Depiction o f the regression lines for flow , pressure , and

efficiency from the Singers Nos . 1 3 and 62 (Tenor Singers ) . The sub­

glottic pressures at high intensities are remarkab ly high , up to 10 kPa

( 100 cmH2

0 ) •

i n order to rema i n �li thi n thei r s i ng i ng vo i ce regi s ter . At each of the vari ous pi tches �1e a h -1ays measured over the compl ete dynami c range .

The aerodynami c data of the t1�o measuri ng seri es from Si nger No . 1 7 have a l ready been recorded i n Fi gure 4- 1 .

I n the eva l uat i o n , the aero­dynami c da ta from the tenors i m­pres s by the i r hi gh s ubgl otti c pres su t·es and l o1� effi ci ency t·e­g res s i on l i ne s , wh i ch l i e " at the l imi t of the rel evant reference

150

a rea , see Fi gure 6- 1 . The regression l i nes from the

other three s i n gers l i e c l ose to the correspondi ng reference re­gres s i on l i nes , s ee F i gure 6 - 2 . They dev iate very l i ttl e from those cal cul ated from the data o f non­t rai ned voi ces .

From Tabl e 6-2 appea rs that the re l at i ve effi c i ency val ues of the s i ngers nea rly a l l a re more or l ess negati ve . The fact that the effi ­c i ency of the wel l produced s i n g i ng vo i ce i s rather l ow , i s s urpri s i ng and unexpected . General ly spea k i ng ,

/ _./

"""' ( 63

l� � q,.l 170Jj F<r. 1.------

ll__-.---

/ � 17o ...-;:; � ;;?"" .............. 11c � _ -::;:.:

�v 3o} , h-' V&3

� � /

/

� �

I .0 q(lls)

.5

/ 0 .2

0 0. OS

v i 0

V;:z� p (kPol

5

P/ I v 0. 5

0. 2

150 70 80 90 100 ! (dB)

0.

/ v .4 � E�

/A �/ / I v / A r/

1�_,/j W/ v 3oP� "/ �. / 1/

!--�

1000 E ( 10"5)

� v i 00

I 0

I

80 70 80 90 100 °1 HdBI

Figure 6-2 . Depiction of the regression lines for flow , pressure , and

effi ciency from the Singers Nos . 3 and 1 7 ( Baritone Singers ) and No . 6 3

( Bass ) .

the aerodynami c data re lat i ng to i n tens i ty and pi tch i n s i ngers a re not di fferent from those i n non­trai ned voi ces .

Bouhuy s , Mead , P roctor et a l . ( 1968) a l s o s tate that the effi ­c i ency i n a wel l - trai ned amateur s i nger was l ower than i n the four non- tra i ned s i ngers exami ned at the same ti me . They gave no fu rther i n formati on .

The l ow effi c i ency va l ues i n the tenor s i ngers measured by us are due to the h i gh subgl o tti c pressures . H i gh s ubgl o tti c pressures (up to 70 cmH20 ) �1ere

a l so seen by P roctor ( 1968 , 1974 ) . From our i n vest i gati on , i t ap­

pea red that the h i gh s ubgl ottic pressures were used i ntentiona l l y by both tenors i f they sang a t the h i gh frequenc i es of thei r tes s i tura , i n order to obta i n the des i red ti mbre , the so-cal l ed " headvoi ce" or a s Mi l l er ( 1977 ) i nd i cated : " l e g i t i mate headvo i ce " . The vo i ce qua l i ty then has the desi red " ri ng" ( see Venna rd , 196 7 ) and i s "we 1 1 -ba l anced " . The dynami c range of these good vocal qual i ty h i gh frequency sounds usua l ly i s not very l a rge and l i es nea r the

15 1

maxi mum obtai nab l e s ound i ntens i ty . A t the l ower freq uenc i es o f the

tenors , when chest voi ce i s used ( " voce pi ena" - M i l l er ; " fu l l voi ce" - Vennard ) , the pressure val ues correspond wi th thos e of other s i ngers and non-trai ned voi ces .

I f at the hi gh frequenci es tones were produced wi th an u na cceptabl e sound qual i ty , e . g . fa l setto- l i ke o r " not-bal anced wi thout ri ng" or "badly pl aced " , l ower press ures were measured , abou t 4 kPa ( 40 cmH20 ) . Th i s means that the l a rynx from an energet i c po i nt of v i ew i s used l es s effi c i ently con­sequently to the purpose of ob­ta i n i ng an optimal aesthet i c sound .

The i nfl uence of the fl owhead mouthpi ece i n the mo uth and the effect of the e l ongati on of the vocal tract by the fl owhead , was studied in a separate seri es of experiments . For th i s purpose , a series of phonati ons was recorded in wh i ch the s i ngers were s tandi ng and wi thout fl owhead cou l d s i ng unconstrai ned . The oesophagus bal l oon had been i nserted vi a the nos e , and , from the pressure vari ­ati ons , the data for the supg l o tt i c pressure were as certa i ned accord i ng to the abrupt ces sati on method i ntroduced by van den Berg ( 19 56 } ,

152

see 2 . 7 . The execution of the cessation manoeuvre caused no probl em whatsoever for the t ra i ned s i ngers and coul d be performed faul tl ess l y after a s hort i n­s tructi on . The measurements com­pri sed an extens i ve dynami c range at vari ous pi tches . I n th i s seri es , the tenor s i ngers used subgl otti c pressures wh i ch were about equa l ly hi gh as those duri ng the compa rabl e phonati ons of the measuri ng seri es performed accordi ng to the s tandard procedure .

Hi gh i ntrathora c i c pressures have an unavoi dabl e i nfl uence on the c i rcul ati on , as is wel l - known from the Va l sal va manoeuvre . I n pho­nati on , especi a l ly wi th h i gh sub­gl otti c press ure i n tenor s i ngers , these i nfl uences wi l l occur . The i nfl uence of subgl otti c press u res on i ntracard i ac b l ood press u res measured duri ng heart catheter­i zat ion has been reported by van den Berg ( 1956 ) .

Subgl otti c pressures ( i ntra­thora c i c pressures ) h i gher than about 3 kPa ( 30 cmH20 ) may be ex­pected to h i nder the refl ux of the bl ood to the heart , wh i ch i n­fl uences the card i a c output . Th i s can b e ascertai ned i nter al i a by regi s teri ng the changes i n the peri pheral ci rcul ati o n , e . g . i n

the thumb , by a photopl ethysmo­graphi c method . To a thumb of Tenor S i nger No . 13 a trans ducer was fas tened (Vasotes t , Groni ngen Un i vers i ty Laboratory for Med i ca l Phys i cs ) and thus the fl uctuati ons i n the ci rcul ati on were regi stered , together wi th the sound s i gnal ( BrUel and Kj aer apparatu s ) on the M i n gograph recorder .

The res u l t i s represented i n Fi gure 6- 3 ; i n the upper pa rt ( A ) are t h e curves o f sound i ntens i ty , a i r fl ow rate , oesophageal press­ure , and l ung vol ume ; in the l ower pa rt ( B ) , from a correspondi ng phonati on , the photopl ethysmogram and the sound s i gna l . The a rm musc l es were rel axed . From thi s fi gure i t appea rs that the ampl i ­tude o f the vas cu l a r pu l sa t i ons i n the thumb decreases very much duri ng the phonation and i ncreases a fter the phonat ion has fi n i s hed , as a s i gn of so- ca l l ed reacti ve hyperaemi a fo l l owi ng the re l ease . I n case of s uch h i gh s ubgl otti c pressures venous congestion of b l oo d in the head a l so deve l opes .

I n a few meas uri ng series , i n wh i c h hi gh s ubglottic pres s ures were a l s o produced , the thumb­p l ethysmogram was recorded s i mu l ­taneously wi th the aerodynami c meas urements . The i nfl uence on the peri phera l ci rcul ation was not

a l ways so unambi guous and di sti nct as in F i gure 6-3 . There certai nly a re many opportuni ti es for further s tudy of th i s matter in genera l .

I n the da i ly performance o f the profess i onal s i nger , h i gh s ub­g l o tti c pressures , which mi ght s upposedly be i nj u ri ous to the l arynx , in fact do not often occur, because , as al ready menti oned , these do occur only i n l oudly s ung h i gh tones . Phonati ons at the same pi tch , wh i ch are to be pro­duced softly , can be sung w ith much l ower subgl ott i c pressure . I f i n s i ng i ng , a l ess heavy voice reg i s ter ( "voce fi nta " - M i l l e r , 19 7 7 ) i s used the i nfl uence on the bl ood c i rcu l at i on i s al so l es s or even absent.

From measurements and from the i nforma tion provi ded by the s i ngers , we rece i ved the impres s i on that i n s i ng i ng provi s i ons are made that the a i r f low remai ns wi th i n certa i n i ndi vi dua l l y determi ned l imi ts i n order to protect the l arynx from i nj ury .

I t i s remarkab l e that i n three measuri ng seri es from Tenor S i nger No . 62 the ai r fl ow rate is nearly i ndependent of the i ntens i ty . The great reproduci b i l i ty i s a l so con­s p i ci ous . The other s i ngers i ndeed do use at l ower i ntens i ti es a l ower fl ow . The rel ation between flow

153

TIME (s)

VOLUME (()

ESOPHAGEAL PRESSURE (kPa)

SOUND INTENSITY (dB)

5.0

2.5

_________ _,..,1 sound 1�

' I I I ' I I I l I I I I I I I ---+t (s)

I ' I ' I '

Figure 6- 3 (A , B ) . The influence of high subglottic pressure on peripheral

circulation :

A . A simultaneous registration of lung volume , oesophageal pressure ,

air flow rate , and sound intensity of one phonation at 440 Hz from a

professional Tenor , ( No . 1 3 ) .

154

A

B

and i ntens i ty seems to be deter­m i ned i ndi v idual l y , as i s the re­l at i on between subgl otti c pressure and i ntens i ty , and to be connected wi th i ndi vi dual di fferences i n the bui l d of the l a rynx .

6.3 Qualitative aspects of the

singing voice

The qua l i ty of the produced tone in s i ngers i s of deci s i ve s i gn i f i ­cance . From va ri ous i nvesti gati ons i t appears that a wel l produced tone has certai n properties . I n that context the v i brato and the mutual rel at ion of the overtones s eem to be the mos t i mportant factors ( \� i ncke 1 , 1952 , 1953 ; Vennard , 1967 , and Sundberg , 1970 , 1977 ) . These characteri st ics can be shown by frequency analys i s of the produced tones . We s tudy a fe�1 tones th i s way and g i ve an examp l e i n 6 . 3 . 1 .

The sound wh i ch ul t imately comes out of the mouth i s model l ed by the vocal tract . The form of the

vocal tract determi nes �1hi ch vowel wi l l be produced . However, the vocal tract and the gl otti s generator ( l a rynx) i nfl uence each other mutua l l y , which under certa i n ci rcums tances l eads to a spec i a l phenomenon wh i ch wi l l b e exten­s i vely deal t with in 6 . 3 . 2 .

6 . 3 . 1 Qual i ty o f the sung tones ; v i bra to and the s i ngi ng formant

A good sung tone appeared to go al ong wi th the presence of a regu l a r vi brato and the ex i stence of harmoni c overtones at about 2500-3500 Hz , see Fi gure 6-4 . Venna rd ( 1967 ) named the qual i ­tat i ve characteri s t i cs o f a good tone "ri ng" . Wi nckel ( 1952 , 195 3 ) and Sunberg ( 1970 ) used the term " s i ngi ng formant " .

The sonagram of Fi gure 6-4A shows the same pattern as the sonagrams deri ved from wel l - produced tones descri bed i n the l i terature ( van den Berg and Venna rd , 1959 ;

B. A photoplethysmogram of the thumb , with relaxed arms , taken while

the subject 1-1as phonating , presented 1vith a simultaneous sound registra­

tion of the phonation produced under identical condi tions as in A. From

the plethysmogram fo"l lows that the heart, because of the high intra­

thoracic pressure , can only keep the circulation going at the cost of

considerable strain .

1 5 5

Venna rd , 1967 ; Large , 1973b ) . For compar i son , Fi gure 6 -4B s hows the sonagram of a non-trai ned Subject ( No . 2) who at the s ame pi tch and sound i ntens i ty produced an i dent­i ca l vowel trans i ti on . Obv i ous ly the s i ngi ng formant i s mi s s i n g , whereas i n the sonagram of the untrai ned person more upper part i a l s a re recorde d .

A n i rregu l a r vi b ra to or the l ac k of i t i nd i cated that the s i ngers produced the tone bad l y . The pres­ence o f the vi brato i s not only vi s i b l e i n the sonagram , but a l so can be read from the curves for fl ow , pres sure , and i ntens i ty ( see Fi gures 6-3 and 6- 5 ) .

6 . 3 . 2 Acous t i c coupl i ng of vocal tract and l a rynx

As al ready menti oned in Chapter 2, some normal s ubjects appeared to experi ence di ffi cul t i es in pho­nation at about 300 Hz . These often cons i s ted of di ffi cul t i es in ma i n­ta i ni ng exactly the requi red pi tch or i n p roduci ng desi red voi ce qual i ty at a gi ven pi tch . Occa­s i ona l l y these di ffi cu l ti es were so severe , that at certa i n notes the voi ce sk i pped i nto another uni ntended regi s te r .

Thes e di ffi cu l t ies are the con­sequence of the arti fi c i a l el an-

156

gati on on the natura l vocal tract ( pharynx and ora l cavi ty ) by the mouthpi ece wi th fl u i d receptac l e and fl owhead . By th i s e longa t i on , a l l the formants wi l l be depres s ed i n frequency and th i s y ie l ds a greater chance that one of the l ower harmoni cs coi nci des exactly wi th a formant resonance pea k and is cons i derably ampl i fi e d . The measured i ntens i ty va l ue may there­fore be l a rger. I s s h i k i ( 1964 ) poi nted th i s out and the e ffect was al ready menti oned i n the d i s ­cus s i on of Fi gure 4-2 .

I n the natural vocal tract the coupl i ng of the vocal tract and the l arynx and the i nfl uence of the acousti c i mpedance and damp i ng factors do not cause a h i ndrance in spea k i ng and s i ngi ng ( van den Berg , 1953 , 1961 ) . At phona tion wi th an el ongated voca l tract these probl ems have to be face d , though , as proved a l ready by Wei s s ' s ex­periments ( 1932a , b ) . Van den Berg exp la i ned thi s phenomenon i n 1954 . I n specia l cases the effect can be so grea t that the fundamental tone i s i nfl uenced , i . e . takes a somewhat di fferent frequency .

Beca use i n our experiments the el ongati on of the vocal tract amounts to 16 em , a di rect i n­fl uence on the fundamental tone of ma l e subjects i s practi cal l y

kHz 8

- 7_ • -

_6_

_s _

_ 4 _

_L_ _2 _

_ 1_ _Q_

A /8/ -- /0/

- - -- - --

-

--+t untrained --+t

Figure 6-4 ( A , B ) . Sonagrams of a trained voice ( A ) and a non-trained voice

( B ) ; ( Sona-Graph Kay Elemetrics Corp . type 606 1-B ) . Phonation took place

at moderate sound intensity at a pitch of E3 ( 165 Hz) . Both subjects made

a vowel transi tion from the vowel /e/ to the vowel /a/ . The formant

shi fts are identical in both subj ects . The vibrato in the trained singing

voi ce is clearly visible as the wave like movements and the "singing

formant" as the dark band in the spectrum at about 2700 Hz, which remains

unaltered even when the vowel has changed .

out o f the ques t i on . I t i s poss i b l e though that one o f the l owest over­tones may co i nci de wi th the l owest forman t .

Because of t h e unavoi dab l e acou s t i c i nfl uence , t h e changes of the sound due to the el ongat ion of the vocal tract and the fi xation of the mouth ori fi ce , the s i nger was depri ved of the use of a number of profess i onal adaptati ons wi th respect to vocal tract and oral ori fi ce . Accordi ng to the subjec­ti ve cri ti cal remarks of the par­ti c i pants themsel ves , thes e l i mi ­tati ons seemed to be of greater i mpo rtance i n l ower s i ngi ng vo i ces

than i n h i gher voi ces . The pl ace and s trength of the

resonance of the addi t i onal vocal tract were s tudi ed by fi tt i ng i t to a n Arti fi c ia l Mouth ( BrUel and Kjaer , type 4219 ) , acti vated by a Beat Frequency Osci l l ator ( BrUel and Kj aer , type 1022) . W i th th i s measuri ng set the frequency char­acteri s t i c was measured from 100 Hz to 10 kHz . The fi rst two resonances were mea sured at 730 Hz ahd 1400 Hz resrecti vel y . Moreover , a s harp anti resonance was ascertai ned at about 2000 H z .

� n phonat ion wi th an e longated vocal tract the tun i ng can be

1 57

al tered by sma l l c hanges i n the vocal cav i t i es , e . g . by a re l ax­ation of the wa l l s of oral or pharyngeal cavi ty , or a s l i gh t sh i ft of the tongue and th i s may l oosen the coup l i ng between el on­gated vocal tract and l a rynx . I n that case the gl otti s generator mai ntai ns the desi red adjus tment wi thout di ffi cu l ty . In normal pho­nation the adaptati ons of the po­s i t ion of the l a rynx and the voca l cavi t i es are of great i mportance for the s i nger , as the s tudies o f Sundberg ( 1970 , 19 7 7 ) have s hown . A great part of the tra i n i ng t ime of a si nger i s devoted to l earni ng to make these ada ptat i ons ( Reg i sterausgl ei ch and Vokal ­ausgl ei ch } .

The i n tens i ty va ri ati ons by maki ng a s l ow gl i ssando wi th the addi t i onal vocal tract f i tted to the natural vocal tract , and try i n g t o ma i nta i n the subglott i c press ure at the same l evel ( subjecti vely } , amounted to abou t + 3 . 5 dB . The greatest sound ampl i fi cation took p lace at a fundamental frequency of about 310 Hz , i . e . at about the l owest formant of the el ongated system.

It is not surpri s i ng that es­pec ia l ly s i ngers experi ence di ffi ­cul ti es at certai n frequenci es and qual i ti es of tone , in vi ew of the i r

158

stri vi ng for perfect ion . I n Tenor Si nger No . 13 , t he

requi rement to produce a tone wi th a spec i fi c qual i ty ( " ri ng " ) at an extremely h i gh fundamental freq uency and a very h i gh i ntens i ty l ed to a cri t i cal s i tuati on , i n wh i ch i t became pos s i b l e for th i s coupl i ng phenomenon to occur . Duri ng the phonati on , the reg i s ­tered sound i ntens i ty suddenl y i ncreased by 10 dB , whereas no changes took pl ace i n fl ow and press u re val ues , see Fi gure 6-5 . The s i nger remarked that he fel t at a certa i n moment a sensat ion as i f hi s l arynx was no l onger under h i s control anymore .

I t i s l i kely that such a phe­nomenon can occur only if a number of factors coi nc i de . Th i s may expl a i n why these extreme probl ems only occurred i n one of our s ub­jects under unusual cond i t i ons and were not observed to th i s extent i n any other s ubject , or cou l d be avoi ded by them wi th a somewhat d i fferent adj ustment of the l arynx or vocal tract . The i nfl uences on the measured aero­dynamic re l at i ons wi l l be sma l l i n general and go l os t i n the i ntra­i ndi vi dual spread i n g .

f

TIME(s)

VOLUM E (I)

ESOPHAGEAL PR ESSURE(kPa)

AIR FLOW RATECI/s)

SOUND INTENSITY(dB)

··· l�� 7.5 \ ��-.��WJJit 5.0 \ 2.5 ·r 0.0

· 2.5 '\ ... 1

0.4] 0.2 li 1%8l \ 80

60 -

I I ' .,.,--..-/

Figure 6-5 . Simultaneous regis tration of lung volume , oesophageal press­

ure , air flow rate , and sound intensity of one phonation at 420 Hz on

the vowel /a/ from a professional Teno r , No . 1 3 . About 3 . 5 seconds after

the onset of the phonation, a sound intensity increase of about 10 dB

was registered in consequence of the resonance phenomenon , discussed in

the text .

The values of the subglottic pressure and the air flow rate did not

change . The regular variations of the oesophageal pressure curve corre­

spond with the vibrato .

6.4 Variants of the singing

voice production

Rub i n , LeCove r , and Vennard s tated i n 196 7 , "An arti st i c s i ng i ng tone i s one pre s umabl y phys i o l og ica l ly and acous t i ca l ly optima l ly produced . I t contrasts

wi th tones more frequently heard 1�h i ch are col ored by vari ous un­des i rab le qual i ti es s uch as breathi ness , constri ction , throati ness , ect . "

The same a uthors descri bed some qua l i tati ve aerody nami c aspects of these aberrant phonati ons ,

159

d i fferi ng from optima l voca l tones . Such vari ants of vo i ce producti on have a lso been i nvest i ga ted , in 1959 , Vennard acti ng as s ubject , by s onagraphy comb i ned wi th rad i o ­graphy o f the pha ryngeal a n d oral cavi t ies , in order to as certai n the changes of the l aryngeal po­s i ti on and the voca l tract ( van den Berg and Vennard , 1959 ; Vennard , 1967 ) .

I n the same s ubject ( among others ) consc i ously produced vari ants of vo i ce producti on were i nvesti gated by transcutaneous el ectromyography of a number of l a ryngeal mus c l es , as wel l as s ome pa l atal muscl es ( Vennard , Hi rano , Oha l a , and Fri tzel l , 1 970a , b , 1971a ,b } .

I n 1978 , van Dei nse and Gos l i n gs produced a sci enti fi c v i deo-fi l m o n the changes i n the voc a l tract in va rious s i ngi ng techni ques . For th i s purpose they used s i deways taken X- ray pi ctures .

Sys temati cal exami nation and reg i s trat ion of the va l ues of the subgl ott i c press ure and fl ow was reported not to be poss i b l e i n the aforementi oned s tudy of Rubi n , LeCover , and Vennard ( 196i) , be­cause of the great i nter- i ndi vi dual and i ntra- i nd i v i dual d i s pers i on of the data . I n Chapter 4 , we

160

demonstrated that an i ntra- i nd i ­v i dual compari son can be made i n a rel i ab l e way i f the res u l ts are compared w ith the normal regress i on l i nes of the same subject .

I n Si nger No . 63 ( Bass ) , the regress i on l i nes were ca l c u l ated from 82 phonati ons . After the normal series , some variants of the s i ng i n g voi ce producti o n were a l s o i nvesti gated , see Fi gure 6-6 .

The va ri ous s i ng ing techn i q ues presented here s how i n the extreme vari ants s ome c l ear di fferences wi th res pect to pressure and flow. As far as the subgl ott i c pre s s u re i s concerne d , we establ i shed a devi ant pattern i n s i nging ac­cordi ng to the so-ca l l ed " Staupri nzi p" . The hi gher s ub­g l otti c press ures though are accompan i ed by l ow fl ow val ues , wi th the consequence that the effi ­ci ency does not devi ate .

Thi s "Staupr inz ip " techn i q ue o f si ng i ng was propagated by Armi n ( 1909 ) but has been rejected gen­era l l y , because i t may l ead to damage of the voi ce . Moreove r , the method can on ly be used in a l imi ted way (Sei dner and Wen d l e r , 1978 ) . E xtens i ve i nves t i gati ons on the "Staupr inz i p" have been made more than 50 years ago by Sch i l l i ng ( 19 22 ) .

I n the tenor s i ngers we found

2!/ / -

( � �� �ilrol r

\ --1.-----�

/ v� ----� �

c v f./-4 \ �

!'--. k::=--4

� �

1.0 q(1/s)

0.5

0.2

0.1

0.05

,/ 1 0

/ � Propj V/' /

p (kPo) 5

0 .5

0 .2

60 70 80 90 100 l (dB)

0

I I / v�

/ VJ / v7 �/ // 1// v

7 [7 1/ I 7

£ Ell! / Xe �/ I

1--lL

1000

E ( 10 1)

v , 00

1 0

1

60 70 80 90 100 [ (dB)

0

Figure 6-6 . Depiction of the regression lines for flow , pressure , and

efficiency from the Singer No . 63 ( Bass ) . The regression lines from the

normal measuring series ( 1 ) , are distinguished by ciphers from the re­

gression lines obtained from the use of various s inging voice techniques :

( 2 ) "verhauchte Einsatze" , ( 3 ) " falsche Atemtechnik" , ( 4 ) "maximale

Rachenwei te " , ( 5 ) "Nasalieren" , ( 6 ) "Stauen" .

very hi gh subg lotti c pressures , but wi thout further i nvesti gati on , thi s i s no suffi c i en t reason to di s card th i s s i ng ing method com­pl ete ly . For the moment , �1e agree wi th Sch i l l i ng ' s conc l u s ion : " Wenn i c h trotz der offens i chtl i chen Gefa h ren das Stauen , ebenso w i e Froes che l s n i cht vol l s tand i g ver­werfe , sondern i hm e i ne berechti gte Stel l ung i n der Gesangspadagogi k ei nraume , so geschi eht es des ha l b , wei l i ch gl aube , das z durch vor-

s i chti ge und a l l mahl i ch gestei gerte StauUbun g , die Kraft und Lei stungs­fah i gkei t der fUr die dynami sch maxima l ges tei gerte Phonation i n Aktion tretenden antagon i s t i s chen Atemmus kul atur ges tah l t und durch ri chti ge koord i nat ive E i ns te l l ung der Ubri gen Stimmuskul atur ( Ent­spannung der Hal s- und Keh l kopf­muskel s ) d i e Gefahren we l che grosze stimml i che Anstrengungen bei un­genUgend t ra i ni erter und unoko­nomisch ei nges tel l ter Atem- und

1 6 1

Stimmus k u l a tur mi t s i ch bri ngen , eher vermi eden werden konnen . "

I n F i gure 6-6 , we observe a de­creas e of the a i r consumpti on as a conseq uence of the so-ca l l ed "Nasa l i erungspri nz ip " ( i nter al i os Pahn , 1964 , 1966 ) by ra i s i ng the i ntens i ty . Becaus e the press u re va l ues do not devi ate from the average , the phonati ons wi th h i gher i ntens i ti es are more effi c i ent s i nce the a i r fl ow decreases . In phonati ons wi th a breathy attack ( verhauchte E i nsatze ) , espec i a l l y a t l ower i ntens i ti es , hi gh a i r fl ow rates were meas ured , for the l owes t i ntens i t i es , even outs i de the reference area for the fl ow . The effi c i enci es of thes e phonat i ons were accordi ng ly l ow .

6.5 Conclusions

a . The effi c i ency of aes thet-i ca l l y good phonati ons at h i gh

sound l e ve l s produced by tra i ned s i ngers in general is l ower than that of phonati ons produced by non­tra i ned voi ces . The effi c i ency of the voi ce seems to be seconda ry to the des i red qual i ty of the voice .

b . I n tenor s i ngers , l oud pho­nati ons in the upper compass

of the voi ce may go a l on g wi th very h i gh s ubgl otti c pres sures , wh i ch

162

have an evi dent i nfl uence on the bl ood c i rcu l at i on .

c . Under exceptional c i rcum-s tances the function of the

l a rynx may be i nfl uenced by the acous t i c properti es of the a rt i ­fi c i a l l y el ongated vocal tract coupl ed to i t .

d . Va ri ants i n s i nging vo i ce techni que , according to

various teachi ng methods , show up in the aerodynami c data .

Chapter 7 Summary

We i nvesti gated the effi ci ency 1nd other aerody nami c aspects of 1oi ce production i n norma l and 1bnormal l a ry nxes .

I n Chapter 1 , a short s u rvey i s j i ven o f the myoel as t i c-aerodynami c :heory of vo i ce producti on , b ri efly i i s c us s i ng the i mportance of a i r Fl ow rate and subgl otti c pressure.

By rel ati ng the power necessary For sound producti on to the pro­iuced sound i ntens i ty , the effi ­: i ency of the l a ryngea l generator :an be ascertai ned . The purpose Jf our stu dy was to estab l i sh to �h i ch degree the effi c i ency i n �ari ou s l aryngea l di s turbances wi l l Je i nfl uenced and to formu l a te :ri ter i a for predi cti ng and eva l u­iti n g the res u l t on effi c i ency of therapeuti c meas ures in our pa­ti ents . Data obtai ned in normal subj ects wi thout vocal compl a i nts have been used for compari son .

In Chapter 2 , the methods em­pl oyed for meas uri ng sound i nten­s i ty , a i r fl ow rate , and subgl ott ic press u re at various pi tches and sound i ntens i ti es over the total vocal compass have been descri bed .

The sound i ntens i ty i s measured by a m i crophone and the a i r fl ow rate by pneumotachography .

For measuring the s ubgl ott i c

pressure we used a n i ndi rect method . The subgl o tti c pres sure was ascerta i ned from the changes i n the oesophageal press u re duri ng and/or after phonati on . The press­ure in the oesophagus a l so vari es w ith vary i n g l ung vol ume , so we had to take th i s l atter i nto account i n the determi nation of subgl o tti c pressure from meas ure­ments of the oesophagea l pressure . The changing l ung vol ume was ascertai ned by i ntegration of the fl ow s i gnal from the pneumotacho­graph .

I n the reg i s tration of vol ume curves , we had to correct for vari ous di fferences i n the phys i ca l properti es of i nsp i red and expi red a i r . Th i s i s theoreti ca l l y ex­pl a i ned and i l l u s trated by ana­lytica l experiments .

Genera l l y , press ure changes due to the v i s cous res i s tance of the l un gs and a i rways are l ow during phona t i on .

By applyi ng a second correcti on method , it was pos s i b l e to com­pensate automat ica l ly the changes in the oesophagea l pressure due to changes i n the l ung vol ume duri ng the measuri ng seri es . Thus the subgl otti c pressure cou l d be read d i rect ly from the corrected oesophageal press ure curve .

The i nd i rect measurement of the

163

subg l otti c pres sure was veri fied on the course of the regress ion by s i mu l taneous di rect measurements l i ne . The data for a l l p i tches i n i n three pati ents . one measuri ng seri es there fore were

converted i nto regress ion l i nes , I n Chapter 3 , the analys i s of the i ntens i ty bei ng cons i dered as

the curves and the accuracy of the i ndependent variab l e . mea s u rements are di s cussed . The fl ow and pressure va l ues and ,

Reduction of the experimenta l therefore , a l so the effi c i ency data from s i ng le phonati ons took va l ues , showed a great i nter- i nd i -pl ace by cal cu l ati ng regression vi dual sprea d . Reproduc i b i l i ty l i nes through the mea s uri ng poi nts . meas u rements showed that the i ntra-These regress i on l i nes apply to i ndi vi dual di fferences a re much the rel at ion between a) the i nten- sma l l er than the i nter- i nd i vi dua l s i ty and b ) respecti vel y , the a i r di fferences and that a good repro-fl ow rate , the s ubgl otti c pressure , duci b i l i ty exi s ts . or the effi c i ency . By stati st ica l eva l uati on of the

The regress i on l i nes were used measurements i n the same norma l to obta i n average va l ues and char- subject, re l i ab i l i ty i nterva l s were acteri s t i c val ues for each subject. ca l cu l ated , enab l i ng us to estab­

l i sh the s i gn i fi cance of thera-Chapter 4 g i ves the resu l ts ob­

ta i ned wi th normal subjects wi thout vocal comp l ai nts . We started wi th 4267 phonati ons from 63 s ubjects i n 93 measuri ng seri es . However , some phonati ons were assessed by trai ned l i s teners as acousti cal l y dev iant . The rema i ni ng data from 2736 we l l -sound i ng phonati ons , obta i ned i n 72 measuri ng series in 24 mal es and 21 femal es , were used to estab l i sh reference val ues and reference areas for the eval u­ation of data from pati ents .

The pi tch of the phonati ons ap­peared to have l i ttl e i nfl uence

164

peuti c resu l ts i n pat i ents . The avera ges of the regress i on

coeffi ci ents of the regres s i on l i nes of al l norma l s ubj ects were used to ascertai n reference re­gress i on l i nes for flow, press ure , and effi c i ency . By referri ng the measured effi ci ency to the refer­ence effi c i ency l i ne , a re l ati ve measure of effi c i ency was obta i ned , whi ch enab l ed us to establ i s h the effi ci ency of a gi ven i nd i v i dual l arynx .

The set o f regress i on l i nes was used to obta i n reference a reas representi ng the di stri but ion

s pread of norma l va l ues . Later a na lys i s o f deviant soundi ng phonati ons proved that the aero­dynam i c data of these phonati ons l ay for the greater part wi th i n the reference areas .

I n tenti ona l ly produced hoarse phonati ons , from normal s ubjects appeared to dev iate c l early from " norma l " aerodynami c val ues of the s ame subject .

As the i ntra- i nd i v i dual di ffe­rences are much smal l e r than the i nter- i ndi vi dual di fferences , we concl uded that a pati ent or a norma l subject may serve as a standard for h ims el f , to ascertai n changes i n the aerody nami c pa ttern , e . g . as the res u l t of treatment.

The obtai ned measuri ng resu l ts were compared wi th data from the 1 i terature .

Chapter 5 gi ves the res ul ts ob­ta i ned in 64 pat i ents in 1 20 measuri ng series compri s i ng 4983 phona ti ons .

The pati ents s howed a great vari ety of l a ryngeal d i s turbances . They �1ere di v i ded i nto three ma i n groups : Group I , pati ents havi ng organi c di sturbances of the vocal fol ds , Group I I , pa ti ents hav i ng norma 1 voca 1 fo 1 ds and , i n mos t cases , s l i ght adducti on di sturb­a n ces , i . e . pa ti ents wi th " func-

tional voi ce disorders " , and Group I I I , pati ents hav i ng normal vocal fol ds , but wi th severe i nnervat ion di s turbances of the l a ryngeal mus cl es .

From each group , the cases of some i nteres t ing pati ents are di scussed i n detai l .

The data o f the fi rst measuri ng seri es were used to ascertai n the d i a gnos t i c va l ue of the aerodynami c data : fl ow and s ubgl otti c pres sure , a l one or i n combi nation ( effi c i ency ) .

The great i nter- i nd i v i dual di s­pers ion in pati ents wi th seemi ngly the same l aryngeal di sturbance , depreci ates the va l ue of s i ng l e data . I t appears that a spec i f i c aerodynami c pattern for a certa i n l aryngeal di sturbance does not exi s t . Th i s a l so means that a s i ng l e measurement can hardly es­tabl i s h the di agno s i s of a vocal d i s turbance . However , s i nce it y i el ds a rough impres s i on about the funct ion ing of the l a rynx i t may reveal a hyperfuncti onal use , as we see from the fact that the subgl ott ic pressure regress i on l i nes from a l l pati ents were found to l i e hi gher than the press ure reference l i ne and i n 59' of the cases to l i e outs i de the reference area .

I n Group I (organi c di sturbances ) ,

165

i n about 30' of the pati ents no aerodynami c di s turbances were di agnosed. Thi s was the case wi th pati ents wi th s l i ght vocal fo l d affecti ons l i ke hyperaemi a or oedema , or some pati ents wi th the cl i ni ca l d i a gnos i s of nodu l es . In more severe d i sturbances , obviously devi ati ng aerodynami c va l ues were measured .

The s ubgl otti c press ure val ues l ay in general too h i g h , the f l ow val ues were much d i s persed . The effi c i ency was about 1 to 6 dB l ower than the reference va l ue , wi th one hi ghly devi ati ng va l ue of - 13 . 5 dB .

I t was remarkabl e that i t made l i tt l e d i fference i n the effi ­c i ency whether the vocal fo l d affection cons i s ted o f l ocal di s­turbances l i ke nodu l es , polyps , cysts , or papi l l omas , or of more extens i ve di s turbances of the surface of the fo l ds . The pos s i ­bi l i ty o f ( dynami c ) gl otti s c l osure appeared to be o f great i mporta nce .

I n Group I I ( functi ona l di s ­turbances ) , i n nea rly a l l pati ents an i ncomp l e te cl osure of the gl otti s was as certai ned . Des p i te these i n compl e te gl otti s cl osures , the fl ow val ues appeared to be de vi ant i n only t�10 cases , �1hereas the subgl otti c pressures i n mos t cases appea red t o b e too h i gh . The

166

effi c i ency l ay rough l y about 4 dB l ower than the reference val ue . Most pati ents i n th i s group re­cei ved voi ce tra i n i ng .

W ith res pect to the pat i ents of Group I I I ( s evere i nnerva t i on d i stu rbances ) a survey has been g i ven of the c l i n i ca l aspects o f un i l ateral o r bi l atera l l aryngeal paraly s i s . In three pati ents wi th a b i l ateral para l ys i s surg i cal wi deni ng of the gl ott i s was necess a ry because of res p i ratory di ffi cul t ies . The effect of the operati on on the eff i c i ency and on pos s i b i l i ti es of commun i cation is di s c ussed . I n thi s group the effi c i ency i n pati ents i n whom no s tati c c l osure of the g l ott i s was effectuated , was about B dB l ower than the reference va l ue . The s ubgl otti c pressure i n this group appeared to be , despi te the pa ra lys i s , remarkably h i gh .

I n 4 7 pat i ents , a s econd meas­u ri ng series was performed , after some form of medi cal ( s urg i ca l ) therapy and/or voi ce tra i n i ng had been g i ven .

A number of these patients were exami ned several times , i n a tota l of 56 measuri ng series after therapy , 2434 phonati ons were obta i ned .

The effi cacy of therapeuti c measures , deri ved from the di f­ference of the rel at i ve effi c i ency va l ues , appeared to be favourab l e i n mos t pati ents , though the re l a ­t i ve effi c i ency va l ues nearly a l ways remai ned negati ve .

I n the pati ents i n whom even a fter treatment comp lete ( dynami c ) g lott i s cl osure was sti l l i m­pos s i bl e , e . g . by a pers i s t i ng ch i n k , an improvement o f the effi ­c iency appeared to be rel ated to a more re l axed phonatory pattern . I n aerodynami c terms , t h i s was rel a ted to the decrease of the subgl otti c pressure . To what extent the fl 0�1 va 1 ues were changed de­pended ma i nl y on the pos s i bi l i ty of a dynami c cl os ure of the g lott i s .

I n Chapter 6 , we di s cuss the res u l ts of i nves ti gati ons wi th fi ve trai ned s i ng i ng vo i ces .

The effi c i ency was compared wi th that of non- trai ned voi ces . We concl uded that the s i ngers produced the sound i n such a way that the effi c i ency was of secondary im­portance to the aestheti c demands .

These q ual i tat i ve demands , es­peci a l ly in the tenor s i ngers l ed to the appearance of ve ry h i gh s ubg l otti c pressures at h i gh sound i ntens i ti es . The i n fl uence of these

very hi gh subgl ott i c press u res on the bl ood c i rc u l a t i on is i nd i cated and demonstrated by photopl ethysmo­graphy . Some q ual i ta t i ve aspects l i ke v i brato and the presence of the s i ng i ng formant were studi ed .

The acousti c coupl i ng of the voca l tract to the l a rynx i s di s cussed w i th respect to the occurrence of a part i cu l a r res onance phenomeno n .

T h e chapter cl oses wi th a d i s ­cuss i o n of aerodynami c aspects of some vari ants of the s i ngi ng vo i ce producti on , based on vari ous pedago g i c techni ques . The effi ­c i e ncy appeared to di ffer l i tt l e i n these vari ants , though di ffi ­cul t i es w i t h respect t o fl ow and pressure val ues coul d be demon­s t rated. Our concl us i on was tha t i n these va riants of the s i ng i ng vo i ce production the subjecti ve and s i nging pedagogi c a spects are of greater i mportance than the ae rodynami c ones .

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Samenvatting

In di t onderzoek worden de effi - gel u idssterkten over de gehe le ci ency van de s temvormi ng en de stemomvang. b i j de stemvormi ng optredende aero- De gel u i dssterkte wordt gemeten dynami s che vers ch i j nse l en b i j met een mi crofoon , de fl ow met een no rma l e en afw i j kende s t rotten- pneumotachograaf. hoofden besproken. Voor het meten van de subgl ot-

In Hoofds tuk 1 wordt een kart overzi cht gegeven van de wi jze waarop vol gens de myoel as ti sche­aerodynami sche theori e het stem­gel ui d tot stand komt . De betekeni s van de l uchts trooms terkte (f low ) e n de subgl otti s che druk wordt beknopt besproken.

Door de energi e , die nodi g i s voor de s temvormi ng , i n verband te brengen met de geproduceerde gel ui dsenergi e , wordt de effi ci ency bepaa l d .

Het doel van het onderzoek was na te gaan in we l ke mate de effi ­c iency door vers chi l l ende l a rynx­aandoeni ngen wordt befnvl oed en wat het effect is van s temthera­peuti sche maatregel en bij pati en­ten . Ter vergel i j k i ng di enen ge­gevens di e op dezel fde wijze ver­kregen �1erden b i j proefpersonen zonder s temk l achten.

I n Hoofdstuk 2 worden de ge­brui kte methoden bes ch reven voor het meten van de ge l u i ds s te rkte , de fl ow en de subgl otti sche druk bij vers chi l l ende toonhoogten en

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t i s che druk wordt een i ndi recte meetmethode gebrui kt . Daarb i j wordt ui t de veranderi ng van de oesophagusdruk bij het foneren de subgl otti sche druk bepaa l d . De druk in de s l okdarm vari eert ti j dens de ademha l i ng in afhanke l i j khei d van het l ongvol ume . Om de s ub­gl otti sche druk betrouwbaar te kunnen meten moet daarom rekeni ng worden gehouden met het l ongvol ume . De veranderi ngen van het l ongvol ume worden geregis treerd door i nte­gratie van het fl ows i gnaa l .

B i j de reg i s trati e van de vol ume­cu rve wordt gecompenseerd voor de vers ch i l l en in fys i sche ei gen­schappen van i n- en ui tademi ngs­l ucht. Deze correcti emethode wordt zowe 1 theoreti sch a 1 s experimenteel geana l yseerd en toegel i ch t .

Drukveranderi ngen a l s gevo l g van de vi s ceuze weerstand van de l ongen en de l uchtwegen z i jn i n het a l ­gemeen k l e i n tijdens de fonati e .

Door een t1�eede correcti emethode toe te pas sen wordt het mogel i j k reeds ti jdens d e meti ngen voor de met het l ongvol ume samenhangende verander i n gen te compensere n . H ier-

door kan de s ubgl otti sche druk di rect ui t de gecorri geerde oesophagusdrukcurve worden a f­gel ezen .

Het i ndi rect bepa l en van de sub­g l o tti s che druk werd geveri fi eerd door gel i j ktijdi g ui tgevoerde d i recte meti ngen b i j een dri etal pati ente n .

I n Hoofds tuk 3 wordt h e t ana­lyseren van de curven besproken en wordt nagegaan met wel ke meet­nawkeuri ghei d de aerodynami s che gegevens en de effi c i ency kunnen worden bepaa l d .

Reducti e van d e meetgegevens van de a fzonderl i j ke fonati es vi ndt pl aats door het berekenen van re­gres s i e l i j nen door de meetpunten . Deze regress i el ij nen geven het verband aan tussen a) de i nten­s i te i t en b) de fl ow , de subgl o t­ti s che druk respecti evel i j k de effi c i ency .

De regress i e l i j nen worden verder in het onderzoek geb rui kt a l s ge­mi ddel de waarden voor de meetge­gevens van i edere persoon ; boven­di en worden hi eru i t kenwaarden a fgel e i d .

D e hoofdzaken van d e presentat ie van de meetresul taten i n gra fi eken en tabel l en worden met en kel e voorbeel den toegel i ch t .

I n Hoofdstuk 4 worden d e res u l ­taten beschreven van 4267 fonaties door 63 normal e proefpersonen zonder s temk l achten , i n 93 meet­seri es . Een deel van de fonaties i s door getrai nde l ui steraars a l s akoes tisch a fwij kend beoordeel d . De res terende gegevens van 2736 goed k l i nkende fonaties , verkregen i n 72 meetseri es bij 24 mannen en 2 1 vrouwen , z i j n gebru i kt voor het vaststel l en van referent i ewaarden en referenti egeb i eden voor het beoordel en van pati entengegevens .

De toonhoogte van de fonati es b l i j kt van wei n i g i nv loed te z i jn op het verl oop van de regres s i e­l i j n . De meetgegevens worden daarom per compl ete meetseri e herl e i d tot regres s i e l i j ne n , waa rbij de i nten­s i tei t a l s onafhankel i j ke vari abel e wordt beschouwd .

De fl 0�1- en drukwaa rden , en di entengevol ge ook de effi ci ency­waarden tonen een grote i nter- i ndi ­vi due l e spre i d i n g . U i t reprodu ­ceerbaarhe i dsmeti ngen bl i j kt dat de i ntra- i nd i vi duel e versch i l l en veel geri nger z i j n en dat een goede reproduceerbaa rhei d bes taa t .

Door stati st i sche bewerk i ng van meti ngen b i j dezel fde proefpersonen werden betrouwbaarhe i ds i nterva l l en vastgeste l d , waa rmee het s i gn i ­fi cant z i j n van het therapiere­s ul taat b i j pati enten kan worden

169

a fgel ezen . U i t de gemi ddel de waa rden van

de regres s i ecoeffi ci enten van de a fzonderl i jke regres s i el i j nen van de proefpersonen werden referentie­regre s s i el i j nen bepaa l d voor de fl ow , de druk en de effi c i ency . Door de gemeten effi c i ency te ver­gel i j ken met de referenti e-effi ­c i encywaarde wordt een re l at ieve effi c i ency-maat verk regen , waarmee de effi ci ency van een bepaa l de l a rynx wordt vastge legd .

D e verzame l i ngen van d e re­gress i e l i j nen van de proefpersonen werden gebru i k t voor het vast­stel l en van referent iegebi eden voor de fl 0�1 , de dru k en de effi c i ency .

Ana lyse van de aerodynami sche gegevens van a fwi j kend kl i nkende fan at i es �1ees ui t , da t deze i n de meeste geval l en b i nnen de refe­renti egebi eden l agen .

Be�1 u st af�J i j kend gep roduceerde fonat i es doo r proefpersonen b l i j ken i n aerodynami s ch opzicht du i del i j k a f te �Ji j ken van de "normaal " waa rden van dezel fde proefpe rsonen.

Mede omdat de i ntra- i nd i v i duel e vers ch i l l en veel geri nger z i j n dan de i nter- i nd i v i duel e versch i l l en , wordt de concl u s i e getrokken dat een pati ent of proefpersoon al s norm kan di enen voor z i chzel f , om veranderi ngen i n het aerodynami sch

170

patroo n , b . v . als gevo l g van een therapeuti sche maatregel , vast te l egge n .

D e verkregen meetresul taten worden vergel eken met de i n de l i teratuur verme l de gegevens .

I n Hoofdstuk 5 worden de resu l ­taten besproken , d i e verk regen werden bij 64 pati enten i n 120 meetseries met i n totaal 4983 fonati es .

De pati enten vertoonden een grate vari ati e aan l arynxaandoeni ngen en werden verdeel d i n dri e hoofd­groepen : Groep I , pati enten met organi sche a fw i j k i ngen aan de stemp l ooi en ; Groep I I , pati enten met gave stemp l ooien en , i n de meeste geval l en , l i chte adducti e­stoorn i s sen , d . w . z . pati enten met " functi one l e s temstoorn i ssen" en Groep I I I , pati enten met ga ve s temp l oo i en , maar met erns ti ge i nnervat ies toorni ssen . Van i edere groep worden enkel e pati enten nader bes proken .

De gegevens van de eerste meet­serie b i j deze pati enten worden gebrui kt voor het vaststel l en van de d iagnosti s che waarde van het meten van aerodynami s che gegevens al s fl ow en s ubgl otti s che druk afzonderl i j k of in comb inati e , zoa l s tot ui tdrukk i ng komt i n de effi c i encywaarde .

De grate i nter- i nd i v idue l e s p re id i ng i n de meetgegevens van proefpersonen respecti eve l i j k pa­ti enten met ogens ch i jn l i j k dezel fde l a rynxaandoe n i n g , maakt de d i ag­nos ti s che waarde van ge1sol eerde meti ngen geri n g . Er bl i j kt geen s peci fi ek aerodynamisch patroon te bestaan voor een bepaal de l a rynxaandoeni ng . Het eenma l i g meten van de aerodynami s che ge­gevens l evert nauwe l i j ks een b i j ­drage tot de di agnos ti ek van s tem­s toorni ssen . Het kan echter wel een g l oba l e i ndruk geven over de werki ng van de l arynx. De re­gress i e l i j nen voor de s ubgl o tti s che druk b l i j ken b i j a l l e pat i en ten hager te l i ggen dan de d ru k re­ferentie-regress i e l i j n en i n 59M van de geva l l en bu i ten de referen­ti e gebi eden te l i ggen .

I n Groep I ( organi s che s toor­ni ssen ) we rden b i j ca 3D� van de pa ti enten geen afwi j k i ngen i n aerodynami sch opzi cht vastgeste l d . Het betreft dan pati enten met k l i ni s ch ni et-erns ti ge s temp l oo i ­aandoeni ngen al s hyperaemi e of oedeem en een dee l van de pati enten met de kl i ni s che di agnose s tem­p l ooi knobbe l s . B i j de meer erns ti ge aandoeni ngen worden i n aerody­nami s ch opzi cht wel dui del i j k a f­wi j kende waa rden gemeten .

De s ubgl otti s che drukwaarden

l i ggen i n het a l gemeen hoog , de fl owwaarden l open sterk ui tee n . D e e ffi c iency b l eek ca 1 d B tot 6 dB l age r te l i ggen dan de re­ferenti e�Jaarde , met een u i tsch i e te r v a n - 1 3 ,5 dB .

Het i s opmerkel i j k dat het voor de e ffi c i ency n i et veel vers chi l maakt of de s templooi aandoeni ng bestaat u i t p l aatse l i j ke a fw i j ­k i ngen al s s templ ooi knobbel s , po­l i epen , cysten of papi l l omen of u i t meer ui tgebrei de afwi j k i ngen van het s templ ooi opperv l a k . Van groat bel ang bl i j kt de mogel i j kh e i d tot dynami sche gl otti ss l ui ti ng .

I n Groep I I ( " functi one le stem­stoorn i s sen" ) werd b i j b i j na al l e pat i en ten een onvol l edi ge s l u i ti ng van de gl otti s vas tgestel d . Het i s evenwe l opva l l end , da t des­ondanks de fl owwaarden s l echts i n b1ee geva l l en a fwi j kend z i j n , terwi j l d e s ubgl otti s che drukwa a r­den mees tal te hoog z i j n . Een mo­gel i j ke verkl a r i ng h i ervan wordt bes proken .

De effi c i ency l i gt g l obaal ca 4 dB l ager dan de referenti ewaa rde .

Voor de besp reki ng van de pa ­ti enten u i t Groep I I I wordt eers t een overzi cht gegeven van de k l i ­n i s che aspecten van enkel z ijd i ge en dubbel zi j d i ge l arynxverl am­mi ngen.

Bij dri e pati enten met een

1 7 1

dubbel z i j d i ge verl ammi ng b l eek in verband met ademprobl emat iek een gl otti s verwi jdende operat ie noodzakel i j k . Het effect van de operat ies op de effi ci ency en op de communi cat iemogel i j kheden wordt besproke n .

B i j de pati enten i n deze groep , waa rb i j geen tota l e ( dynami s che ) gl otti ss l ui ti ng tot s tand kwam , �1as de effi c i ency ca 8 dB l a ger dan de referent i ewaarde . De s ub­gl otti s che drukken b l i j ken b i j deze groep , ondanks de verl ammi n g , op­merke l i j k hoog .

B i j 4 7 pati enten i s ook een mee t­seri e gedaan , nadat een vorm van medi sche ( ch i rurg i s che ) en/of l ogo­pedi s che therapi e was gegeven . Een aantal pati enten is vaker onder­zoch t , i n totaal z i"j n 56 meetseries na thera p i e opgenomen , met i n totaal 2434 fonati es .

De i nvl oed van therapeuti s che maa trege l en , afgel ei d u i t het verschi l van re l ati eve effi c i ency­waarden , b l i j k t b i j de meeste pa­ti enten guns ti g , hoewel de re l a­tieve effi ci encywaarden vri j1�el al ti jd neg negat ief z i j n .

B i j pati enten waarb i j ook na therap i e geen tota l e ( dynami s che ) gl otti ss l ui ti ng mogel i j k i s , b . v . doo r een aan de dors a l e zi jde openbl i j vende gl otti s , b l i j kt een

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verbeteri ng van de effi c i ency s amen te hangen met een meer ontspannen fonere n . Dit bl i j kt in aerody­nami sche termen samen te ha ngen met het dal en van de subgl otti s che dru k . I n hoeverre de fl owwaa rden da l en hangt vooral samen met de mogel i j kheden tot dynami sche gl otti s s l u i ti ng en de grootte van de s ubgl otti s che dru k .

I n Hoofdstu k 6 wordt het re­s ul taat bes proken van onderzoe­k i ngen b i j v i j f getra i nde zange rs . De eff ic i ency wordt daarb ij ver­gel eken met d i e van n i et- getra i nde s temmen.

Het b l i jkt dat de effi ci ency van de s temvormi ng door de zangers onderges chi kt gemaakt wordt aan de estheti sche ei sen aan de ge­zongen toon .

Deze kwal i tati eve e i sen b l i j ken met name bij de twee zangers­teno ren te kunnen l e i den tot het optreden van ( zeer ) hoge s ub­gl otti s che drukken . De i nv l oed van deze hoge subgl otti sche dru kken op de b l oedci rcu l at i e wordt na­gegaan door fotopl ethysmografi sch onderzoek van de bl oeddoorstromi ng in een duim .

Enkel e kwal i tati eve aspecten van �en goede zangtoon , zoa l s de aan­wez i ghei d van v i brato en van de zg . zangformant , worden besproke n .

De akoesti s che koppe l i ng van het aanzetstuk en de l a rynx wordt aan de hand van het optreden van een resonanti efenomeen bes proken .

Het hoofdstuk wordt bes l o ten met het bespreken van aerodynami s che aspecten van va ri anten van de zang­s temvormi ng , d ie in het al gemeen berusten op vers chi l l en i n zang­pedagogi s che techni eken . De effi ­ci ency bl i jk t b i j deze va ri anten wei n i g te versch i l l en , hoewel ve rs chi l l en i n de fl ow- en druk­waarden wel aantoonbaar z i j n . Vastgestel d wordt dat b i j deze vari a nten van de zangs temvormi ng de s ubject i e ve en zangpedagogi s che aspecten van grater bel ang z i j n dan d e aerodynami s ch e .

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f ·

I

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192

Table 4- 3 . Table of characteristic values of the regression lines from all measuring series from normal subjects . Subject number, sex, interval in months between successive measuring series , and the number of instances of phonation per measuring series have been represented together

with the intensity range and the intensity value for the middle of the range . The characteristic values have been given for flow , pressure , and

efficiency . The last column records the difference in dB at Im

( Ere ! ) between each efficiency regression line and the calculated reference

regression line , see 3 . 6 .

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0 . 9

1 . 3 1 7

1 . 44 9

1 . 1 0 5

0 . 6 1 8

1 . 67 3

2 . 05 2

1 . 1 87

0 . 76 1

1 . 7 1 8

1 . 88 9

0 . 1 92

1 . 1 1

0 . 62 3

1 . 59

2 . 26

0 . 24 1

0 . 82 8

0 . 68 1

1 . 02 7

- 0 . 1 9 2

0 . 409

0 . 97

1 . 922

1 . 86 3

2 . 285

1 . 19

2 . 38 1

- 0 . 1 2 6

1 . 858

- 0 . 1 36

1 . 288

2 . 776

1 . 32 5

- 0 . 9 9

- 0 . 4 1 3

0 . 70 2

1 . 7 1 4

1 . 1 5

1 . 49

2 . 45 1

0 . 1 9 0

1 . 766

0 . 76

0 . 63 4

1 . 6 9

0 . 4 1 1

1 . 34 3

3 . 3 3 3

1 . 269

1 . 29 3

0 . 998

0 . 05 1

0 . 1 72

- 0 . 1 9 7

1 . 3 4 7

1 . 94 5

0 . 577

1 . 49 3

1 . 2 1 9

1 . 6 1 1

1 . 63 7

1 . 1 4 7

0 . 1 9 2

0 . 03 2

0 . 079

1 . 8 1 9

A I R FLOW RATE

a 1 e.s.d.e.

0 . 758

1 . 37:2

l u!

1 . 033

1 . 589

1 . 727

1 . 37

! . 2 1 :::,

1 . 4 :29

1 . 89 :2

1 . 02

0 . 653

1 �­. ..,..,

1 . 94 7

1 . 1 :25

0 . 9 1 :5

2 . 069

1 . 4 76

1 . 794

0 . 988

0 . 476

:2 . 377

1 . 733

1 . 902

1 . 556

2 . 366

2 . 006

1 . 4 3

0 . 8 1 9

0 . 809

0 . 66 1

1 . 005

0 . 31:!

2 . 466

0 . 926

2 . 33 4

1 . 292

0 . 06 2

1 . 1 4 7

3 . 006

2 . 6 1 5

1 . 733

0 . 667

1 . 1 3 6

0 . b�lb

- 0 . 054

1 . 326

0 . 8 1 2

1 . 778

1 . 92 1

0 . 99 0

1 . 908

1 . 25 1

0 . 02 7

1 . 3 37

1 . 30 3

1 . ?98

2 . 0()5

2 . 1 62

2 . 288

1 . 1 3 1

1 . 038

1 . 7 45

1 . 299

1 . 2 1 7

0 . 99 2

0 . 98

1 . 4 28

2 . 2 2 1

2 . 387

2 . 32 1

0 . 8 79

0 . 1 6

0 . ).3

0 . 1 3

0 . 1

0 . 1 2

0 . 1 3

0 . 1 5

0 . 1 2

0 . 07

0 . 09

0 . 1 4

0 . 1 9

0 . 1 3

o . o•J

0 . 1 ::!

0 . 1

0 . 1 3

0 . 1

0 . 1 3

0 . 1 7

0 . � 4

0 . 2 7

0 . 2 1

0 . 1

0 . 1 3

0 . 1 7

0 . 1 7

0 . 1 1

0 . 1 3

0 . 1 4

0 . 1 5

0 . 1 3

0 . 1

0 . 1 5

0 . 07

0 . 07

0 . 09

0 . 2 1

0 . 1 8

0 . 1

0 . 1

0 . 1 1

0 . 1 3

0 . 1 7

0 . 2 1

0 . 1 0

0 . 1 4

0 . 26

0 . 1 7

0 . 1 1

0 . 1 3

0 . 1 3

0 . 1 2

0 . 1 3

0 , 1 6

0 . 09

0 . 1 3

0 . 1 7

0 . 06

0 . 1 2

0 . 1 6

0 . 07

0 . 1 3

0 . 1

0 . 1 6

0 . 09

0 . 1 4

0 . 07

0 . 1

0 . 1 2

0 . 08

0 . 1

ml/s

235

1 77

:.�27

1 9 '1

295

288

2f:J2

225 208

245

237

2 1 7

266

356

292

266

1 66

206

1 95

1 66

230

366

2 1 5

3 1 ::.!

259

1 63

209

1 4 9

253

208

263

252

372

231

264

1 7 1 2 0 1

1 4 8

1 40

1 7 5

1 89

205

1 1 4

1 1 4

67

76

130

126

257

280

1 90

168

155

289

1 86

1 79

1 2 8

1 1 0

198

138

1�4

384

1 55

2 / 1

1 3 2

1 65

222

263

2 4 1

259

245

195

b

xl0-2 3 . 2'i'

2 . 746

2 . 428

2 . 385

2 . 271

2 . 434 ,., ... , c­... . ... ..J

2 . 333

� . 1

2 . 006

2 . 764

2 . 387

1 . 893

1 . 683

2 . 4 56

3 . 1 2

3 . 093

2 . 95

:2 . 65 3

1 . 754

2 . 872

2 . 809

2 . 726

4 . 535

3 . 4 23

2 . 04 2

2 . 4bJ

2 . 249

2 . 389

2 . 073

2 . 608

2 . 28 1

2 . 753

2 . 577

:! . 593

1 . 579

2 . 67

1 . 9

1 . 982

0 . 85 1

0 . 982

2 . 67

3 . 6 1 3

2 . 537

2 . 93

2 . 8 1 1

2 . 593

1 . 90:!

2 . 1 58

2 . 3 1 8

2 . 37

2 . 835

2 . 062

2 . 899

2 . 03

2 . 8 "7

2 . 48 1

1 . 855

2 . 548

2 . 54 2

2 . 406

2 . 324

1 . 8 22

2 . 376

1 . 92 1

2 . 897

2 . 34 2

2 . 575

3 . 1 8 1

3 . 3 1 5

4 . 25

3 . 338

SUBGLOTTIC PRESSURE

a , e.s.d.e.

·-2 . 3

- 2 . 1 9 3

- 2 . 022

- 2 . 08 1

- 2 . 003

- 2 . 1 5 4

- 1 . 992

- 2 . 084

- 1 . 859

- 1 . 746

- 2 . 4 1 '1

- 2 . 033

- 1 . 53 3

- 1 . 465

- 1 . 997

- 2 . 473

- 2 . 5 1 7

- 2 . 4 1 8

- 2 . 1 7 2

- 1 t 586

- 2 . 449

- 2 . 488

-2 . :=i59

-3 . 735

- 2 . 20 1

- 1 . 764

�2 . 026

1 . 84 1

- 1 . 929

- 1 . 6 71

- 2 . 1 1

- 1 . 84'1

- 2 . 403

- 2 . 065

-2. 1 2 1

- 1 . 5 87

- 2 . 4 4 1

- 1 . 56 3

-1 . ,S5'il

- 0 . 929

- 0 . 899

2 . 22 1

- 2 . 996

- 2 . 1 3 7

- 2 . 465

- 2 . 4 1 2

- 2 . 1 8 3

- 1 . 547

- 1 . 774

- 1 . 969

- 2 . 06

- 2 . 346

- 1 . 83

-2 . 409

- 1 . 745

- 2 . 378

-2 . 085

- 1 . 726

-· 2 . 20 3

- 2 . 2�8

-2 . 048

- 1 . 956

- 1 . 4 48

-2 . 1 44

- 1 . 808

-2 . 27 1

- 1 . 84 1

- 2 . 1

- 2 . 564

-2 , 634

-3 . 3 7 1

- 2 . 897

0 . 1 1

0 . 1 8

0 . 1 5

0 . 09

0 . 1 1

0 . 1 4

0 . 1 4

0 . 1

0 . 1 1

0 . 1 2

0 . 08

0 . 1 2

0 . 09

0 . 07

0 . 1

0 . 1 2

0 . 06

0 . 1 1

0 . 1 2

0 . 1

0 . 1 3

0 . 1 4

0 . 2 1

0 . 1 2

0 . 1 3

0 . 09

0 . 07

0 . 1 1

0 . 1 4

0 . 1

0 . 09

0 . 1

0 . 1 5

0 . 08

0 . 1

0 . 1

0 . 1

0 . 07

0 . 1

0 . 1 7

0 . 1 5

0 . 1 2

o . 1 2

0 . 1 1

0 . 2

0 . 1 1

il . 1 7

0 . 1 4

0 . 09

0 . 1 1

0 . 1 4

0 . 08

0 . 07

0 . 1 2

0 . 1 7

() . 1 2

0 . 07

0 . 1 1

0 . 06

0 . 08

0 . 0 7

o . o8

0 . 1 :.!

0 . 1 5

0 . 1 1

0 . 1 2

o . 1

0 . 0 7

0 . 1 9

0 . 1 5

0 . 23

0 . 1 1

kPa 0 . 8 1

0 . 78

0 . 68

0 . 67

0 . 7 4

0 . 67

0 . 7 1

o . 56

0 . 68

0 . 74

0 . 66

0 . 84

0 . 77

0 . 75

0 . 83

1 . 06

0 . 79

0 . 64

0 . 87

0 . 58

0 . 89

0 . 49

0 . 26

1 . 62

1 . 48

0 . 74

0 . 72

0 . 76

1 . 1

1 . 02

0 . 79

0 . 85

1 . 35

1 . 05

0 . 92

0 . 4

0 . 45

0 . 76

0 . 69

0 . 53

0 . 8

0 . 96

o . as

0 . 78

0 . 68

0 . 64

0 . 73

0 . 69

1 . 02

0 . 9

0 . 54

0 . 7 1

0 . 4 1

0 . 5 1

0 . 56

0 . 54

0 . 84

0 . 4 7

0 . 6 1

0 . 47 0 . 6 9

0 . "78

0 . 9

0 . 46

0 . 4 1

o . a5

1 . 3

1 . 34

1 . 33

1 . 36

2 . 02

0 . 4 9

b

xl0-2 4 . 587

6 . 09'1

6 . 06 3

6 . 033

6 . 66 2

6 . 266

6 . 43 3

6 . 2 1 8

6 . 795

7 . 3 76

5 . 56 3

5 . 56 1

6 . 92

7 . 556

5 . 825

4 . 99 1

6 . 7 1 4

5 . 94

6 . 724

6 . 647

4 . 868

6 . 95

6 . 4 4 6

4 . 784

5 . 55

8 . 1 4 9

7 . 1 2 8

6 . 78 1

5 . 689

6 . 06 4

5 . 1 0 7

5 . 929

4 . 866

7 . 549

5 . 549

8 . 557

6 . 04 3

5 . 35

6 . 69 3

1 0 . 1 4

9 . 43 2

6 . 62 9

4 . 673

6 . 3 1 3

5 . 58 1

4 . 73 8

6 . 409

6 . 33 1

7 . 077

7 . 04 8

5 . 93 4

6 . 7 1 3

6 . 595

3 . 768

6 . 70 1

5 . 83 7

6 . 52 1

8 . 095

7 . 28

7 . 655

6 . 2 4 7

5 . 73 1

7 . 60 1

6 . 1 3

6 . 86 1

5 . 492

6 . 02 1

6 . 278

6 . 627

6 . 65 3

5 . 67 1

4 . 84 2

EFFICIENCY

a 1 e.s.d.e.

- 3 . 006

-4 . 02

- 4 . 0 1 9

- 3 . 39 3

- 4 . 427

- 4 . 4 1 3

-4 . 2 1 8

-3 . 972

-4 . 4 1

- 4 . 987

- 3 . 44 2

- 3 . 46 1

- 4 . 84 2

-5 . 323

-3 . 969

-3 . 28 1

- 4 . 394

- 3 . 899

- 4 . 464

- 4 . 24 3

- 2 . 867

- 4 . 73

- 4 . 0 1 5

-3 . 008

- 3 . 707

- 5 . 4 4 3

-4 . 82 1

- 4 . 43

-3 . 73

- 3 . 979

- 3 . 392

- 3 . 997

- 2 . 8 1 8

- 5 . 242

-3 . 646

- 5 . 589

-.3 . 692

-3 . 34

- 4 . 329

- 6 . 9 1 7

-6 . 556

- 4 . 35 2

--2 . 5 1 3

- 3 . 84 1

-3 . 0 3 2

- 2 . 375

-3 . 98 3

- 4 . 1 0 6

- 4 . 845

- 4 . "793

- 3 . 779

-4 . 4 02

- 4 . 26 1

-2 . 459

- 4 . 4 3 3

-3 . 766

- 4 . 053

- 5 . 1 2

- 4 . 8

- 4 . 87 1

- 3 . 924

-3 . 923

- 5 . 1 38

- 3 . 995

- 4 . 25 1

-3 . 56 2

- 3 . 979

- 4 . 1 69

- 4 . 498

- 4 . 593

-3 . 79 1

- 2 . 8 2 4

0 ••

0 . 24

0 . 2 1

0 . 1 3

0 . 2

0 . 2 1

0 . 2 1

0 . 1 9

0 . 1 5

0 . 1 6

0 . 1 8

0 . 2 1

0 . 1 5

0 . 1 3

0 . 1 8

0 . 1 2

0 . 1 4

0 . 1 8

0 . 1 8

0 . 26

0 . 27

0 . 33

0 . 28

0 . 1 8

0 . 1 8

0 . 1 7

0 . 1 9

0 . 1 5

0 . 2 1

0 . 2

0 . 2 1

0 . 1 9

0 . 1 2

0 . 1 6

0 . 1 2

0 . 1 2

0 . 1 5

0 . 2 1

0 . 2 1

0 . 1 3

0 . 1 6

0 . 1 6

0 . 2

0 . 2

0 . 27

0 . 1 7

0 . 2

0 . 35

0 . 1 8

0 . 1 6

0 . 1 3

0 . 1 8

0 . 1 5

0 . 1 6

0 . 1 3

0 . 1 7

0 . 1 4

0 . 23

0 . 07

0 . 1 5

0 . 1 6

0 . 1

0 . 1 9

0 . 1 7

0 . 23

0 . 1 2

0 . 1 9

0 . 1 2

0 . 1 2

0 . 1 4

0 . 22

0 . 1 4

Table 4-4 . Table of characteristic values of the regression lines from normal subjects with more than one measuring seri es . ( For legends see

Table 4-3 ) . The 27 calculated differences , between the successive values of Ere!

from each subj ect in thi s table , have been used for estab­

lishing the significance limits , see 4 . 3 . 3 . 2 .

CD

u CD

il l� � :s' � Cl)

CD ii E M

M

M

2 M

2 M

2 M

2 M

2 M

2 M

2 M

3 M

3 M

8 M 8 M

9 v

9 v

1 0 v

lO V 1 ;! M

1.2 M

1. 3 M

1. 3 M

1.6 M

1 6 M

1 7 M

1.7 M

1 8 M

18 M

26 v

;!6 v

27 v

:!.7 v

28 v

28 v

30 v

30 v

35 M

35 M

49 v

49 v

50 v

50 v

6 1 M

61 M

62 M

62 M

62 M

In .c -c 0 E � s .E

In c 0 � c 0 .c c. 0 0 z

0 3 4

1 8 9

1 0 46

0 4 5

4 4 5

7 60

0 87

2 1 4 9

1 1 2 8

3 3 0

0 4 1

1 1 9 5

0 1 9

4 2 9

0 2 7

6 2 6

0 1 7

2 2 1 6

0 5 7

1 1 4 3

0 25

0 49

0 47

6 4 3

0 7 3

1 78

0 5 1

0 65

0 18

5 2 1

0 2 4

2 3 6

0 46

5 3 9

0 36

5 28

0 27

0 38

0 37

1 32

0 1 9

2 25

0 3 4

1 46

0 3 5

0 5 0

0 1 9

Intensity- I Tm

range

dB

60 - 92 64 - 88

60 - 9 3

60 - 1 0 0 65 - 1 0 0

6 1 - 1 0 2

6 1 - 1 0 3

58 - 99

66 - 95

62 - 99

59 - 1 0 3 59 - 1 0 5

64 - 92

68 - 92 64 - 92

60 - 9 1

6 3 - 96

60 - 94

61 - 9 4

60 - 85

70 - 1 04

59 - 1 0 8

60 - 9 3

59 - 94

62 - 1 0 3

59 - 1 03

60 - 9 4

6 1 - 9 5

64 - 88

62 - 89

68 - 86

66 - 97

60 - 1 0 5

60 - 1 02

60 - 97

65 - 9 3

65 - 1 00

60 - 1 0 6

60 - 1 0 2

6 3 - 88

68 - 88

65 - 87

64 - 1 03

74 - 99

65 - 1 0 4

6 3 - 1 0 4

7 2 - 1 0 1

dB

76 . 2

76 . 2

76 . 2

80 . 8

80 . 8

80 . 8

80 . 8

80 . 8

80 . 8

80 . 8

8 1 . 5

8 1 . 5

79

79

76 . 8

76 . 8

78 . 3

78 . 3

75

75

85 . 3

85 . 3

76 . 5

76 . 5

8 1 . 8

8 1 . 8

77 . 5

77 . 5

75 . 8

75 . 8

79 . 3

79 . 3

8 1 . 8

8 1 . 8

78 . 8

78 . 8

8 2 . 8

8 2 . 8

78 . 3

78 . 3

77

77

85

85

84 . 8

8 4 . 8

84 . 8

b

xl0-2 2 . 1 2 2

1 . 1 5 5

1 . 5 1

1 . 58 3

1 . 067

0 . 9

1 . 3 1 7

1 . 4 4 9

1 . 1 0:5

0 . 6 1 8

1 . 67 3

2 . 05 2

1 . 7 1 8

1 . 889

0 . 1 9 2

1 . 1 1

0 . 62 3

1 . 599

0 . 24 1

0 . 828

0 . 68 1

1 . 027

0 . 409

0 . 97

1 . 92 2

1 . 86 3

2 . 2 8 5

1 . 79

2 . 776

1 . 325

- 0 . 99

- 0 . 4 1 3

0 . 70 2

1 . 7 1 4

1 . 4 9

2 . 45 1

0 . 765

0 . 63 4

0 . 998

0 . 05 1

0 . 1 72

- 0 . 1 9 7

1 . 63 7

1 . 1 4 7

0 . 1 92

0 . 03 2

0 . 079

AIR FLOW RATE

a

0 . 758

1 . 372

1 . 2

1 . 03 3

1 . 589

1 . 72 7

1 . 3 7

1 . 2 1 5

1 . 42 9

1 . 89 2

1 . 02

0 . 65 3

1 . 1 2 5

0 . 9 1 3

2 . 069

1 . 4 76

1 . 794

0 . 988

2 . 377

1 . 733

1 . 90 2

1 . 556

2 . 006

1 . 43

0 . 8 1 9

0 . 80 9

0 . 66 1

1 . 00 5

0 . 062

1 . 1 47

3 . 006

2 . 6 1 5

1 . 73 3

0 . 667

0 . 656

- 0 . 05 4

1 . 778

1 . 92 1

1 . 298

2 . 005

2 . 1 6 2

2 . 288

0 . 98

1 . 42 8

2 . 22 1

2 . 38 7

2 . 3 2 1

e.s.d.e.

0 . 1 6

0 . 1 3

0 . 1 3

0 . 1

0 . 1 2

0 . 1 3

0 . 1 5

0 . 1 2

0 . 07

o . o9

0 . 1 4

0 . 1 9

0 . 1 2

0 . 1

0 . 1 3

0 . 1

0 . 1 3

0 . 1 7

0 . 27

0 . 2 1

0 . 1

0 . 1 3

0 . 1 7

o . 1 1

0 . 1 3

0 . 1 4

0 . 1 5

0 . 1 3

0 . 2 1

0 . 1 8

0 . 1

0 . 1

0 . 1 1

0 . 1 3

0 . 2 1

0 . 1 8

0 . 1 7

0 . 1 1

0 . 1 3

0 . 1 7

0 . 06

0 . 1 2

0 . 1 4

0 . 07

0 . 1

0 . 1 2

o . oa

ml/s

238

1 78

224

205

283

284

272

243

2 1 0

246

242

2 1 2

304

254

1 6 5

2 1 3

1 9 1

1 7 4

3 6 1

2 2 6

304

270

209

1 4 9

246

2 1 5

270

247

1 4 7

1 4 2

1 6 6

1 93

203

1 1 7

68

75

258

279

1 2 0

1 1 1

1 97

1 3 7

235

253

242

259

244

b

x10-2 3 . 29

2 . 7 46

2 . 428

2 . 385

2 . 271

2 . 434

2 . 25

2 . 333

2 . 1

2 . 006

2 . 764

2 . 387

2 . 456

3 . 1 2

3 . 093

2 . 95

2 . 653

1 . 754

2 . 809

2 . 726

4 . 535

3 . 423

2 . 463

2 . 249

2 . 389

2 . 073

2 . 608

2 . 28 1

1 . 9

1 . 982

0 . 85 1

0 . 982

2 . 67

3 . 6 1 3

2 . 93

2 . 8 1 1

2 . 1 5 8

2 . 3 1 8

2 . 48 1

1 . 855

2 . 548

2 . 542

2 . 342

2 . 575

3 . 1 8 1

3 . 3 1 5

4 . 25

SUBGLOTTIC PRESSURE

a

-2 . 593

-2 . 1 93

- 2 . 022

- 2 . 08 1

- 2 . 00 3

- 2 . 1 54

- 1 . 992

- 2 . 084

- 1 . 859

- 1 . 746

- 2 . 4 1 9

-2 . 033

- 1 . 997

- 2 . 473

-2 . 5 1 7

-2 . 4 1 8

-2 . 1 72

- 1 . 586

- 2 . 488

- 2 . 559

- 3 . 735

-2 . 689

- 2 . 026

- 1 . 84 1

- 1 . 929

- 1 . 67 1

2 . 1 1

- 1 . 849

-1 . 563

- 1 . 659

- 0 . 9::! 9

-0 . 899

-2 . 221

- 2 . 996

- 2 . 465

-2 . 4 1 2

- 1 . 774

- 1 . 969

- 2 . 085

- 1 . 726

-2 . 203

- 2 . 258

- 1 . 8 4 1

-2 . 1

-2 . 564

- 2 . 634

-3 . 37 1

e.s.d.e.

0 . 1 1

0 . 1 8

0 . 1 5

0 . 09

0 . 1 1

0 . 1 4

0 . 1 4

0 . 1

0 . 1 1

0 . 1 2

0 . 08

0 . 1 2

0 . 1

0 . 1 2

0 . 06

0 . 1 1

0 . 1 2

0 . 1

0 . 1 4

0 . ::.! 1

0 . 1 2

0 . 1 3

0 . 07

0 . 1 1

0 . 1 4

0 . 1

0 . 09

0 . 1

0 . 07

0 . 1

0 . 1 7

0 . 1 5

0 . 1 2

0 . 1 2

0 . 2

0 . 1 1

0 . 09

0 . 1 1

0 . 07

0 . 1 1

0 . 06

o . o8

0 . 1

0 . 07

0 . 1 9

0 . 1 5

0 . 23

kPa

0 . 82

0 . 79

0 . 67

0 . 7

0 . 68

0 . 65

0 . 67

0 . 63

0 . 69

0 . 75

0 . 68

0 . 82

o . 88

0 . 98

0 . 72

0 . 7

0 . 8

0 . 6 1

0 . 42

0 . 3 1

1 . 36

1 . 7

0 . 72

0 . 76

1 . 06

1 . 06

0 . 8 1

0 . 83

0 . 75

0 . 7

0 . 56

0 . 76

0 . 92

0 . 91

0 . 7

0 . 63

1 . 03

0 . 89

0 . 72

0 . 53

0 . 57

0 . 5

1 . 4 1

1 . 23

1 . 36

1 . 5

1 . 71

b

xl0-2 4 . 587

6 . 099

6 . 06 3

6 . 03 3

6 . 662

6 . 666

6 . 43 3

6 . 2 1 8

6 . 795

7 . 376

5 . 56 3

5 . 56 1

5 . 825

4 . 99 1

6 . 7 1 4

5 . 94

6 . 724

6 . 6 47

6 . 95

6 . 4 46

4 . 784

5 . 55

7 . 1 2 8

6 . 78 1

5 . 689

6 . 06 4

5 . 1 07

5 . 929

5 . 3:! 5

6 . 693

1 0 . 1 4

9 . 4 32

6 . 629

4 . 6 73

5 . 581

4 . 738

7 . 077

7 . 048

6 . 52 1

8 . 09:5

7 . 28

7 . 655

6 . 02 1

6 . 278

6 . 627

6 . 653

5 . 671

EFFICIENCY

a

-3 . 006

- 4 . 0 2

- 4 . 0 1 9

-3 . 79 3

-4 . 427

- 4 . 4 1 3

- 4 . 2 1 8

-3 . 972

-4 . 4 1

4 . 987

-3 . 44 2

- 3 . 46 1

- 3 . 969

- 3 . 28 1

- 4 . 394

- 3 . 899

-4 . 464

- 4 . 24 3

- 4 . 73

- 4 . 0 1 :5

- 3 . 008

- 3 . 707

- 4 . 82 1

- 4 . 43

- 3 . 73

- 3 . 979

3 . 392

- 3 . 997

-3 . 34

- 4 . 329

-6 . 9 1 7

6 . 556

- 4 . 352

2 . 5 1 3

-3 . 032

2 . 375

- 4 . 845

4 . 79 3

- 4 . 05 3

5 . 1 2

4 . 8

4 . 87 1

- 3 . 979

- 4 . 1 6 9

-4 . 498

- 4 . 593

-3 . 791

e.s.d.e.

0 . 2

0 . 2 4

0 . 2 1

0 . 1 3

0 . 2

0 . 2 1

0 . 2 1

0 . 1 9

0 . 1 5

0 . 1 6

0 . 1 8

0 . 2 1

0 . 1 8

0 . 1 2

0 . 1 4

0 . 1 8

0 . 1 8

0 . 26

0 . 33

0 . 28

0 . 1 8

0 . 1 8

0 . 1 9

0 . 1 5

0 . 2 1

0 . 2

0 . 2 1

0 . 1 9

0 . 2 1

0 . 2 1

0 . 1 3

0 . 1 6

0 . 1 6

0 , 2

0 . 27

0 . 1 7

0 . 1 8

0 . 1 6

0 . 1 4

0 . 23

0 . 07

o . 1 5

0 . 1 9

0 . 1 2

0 . 1 6

0 . 1 4

0 . 22

xl0-5 3

4 . 1

4 ••

1 0 .

1 1 .

1 0 . 5

1 1 . 4

8 . 1

1 1 . 5

8 . 9

1 1 . 6

1 2 . 6

2 . 2

4 . 8

3 . 8

5 . 1

7

3 . 9

7 . 6

7 . 5

1 5 . 8

4 . 5

4 . 6

1 4 . 2

8 . 5

1 1 . 9

4 . 3

5 . 7

9 . 2

8 . 6

3 . 5

4 . 2

45 . 6

7 . 5

6 . 6

6 . 8

1 1 . 3

5 . 1

5 . 3

7 . 8

1 3 . 5

1 3 . 1

1 8 . 7

1 6 . 2

2 2 . 3

23 . 4

1 2

3 . 3

9 . 8

1 1 . 4

5

6 . 8

2 . 3

2

3 . 1

3 . 3

1 6 . 9

9 . 8

7 . 6

8 . 8

9 . 5

4 . 3

5 . 2

4 . 6

6 . ?

4 . 1

1 1 . 2

1 8 . 3

1 2 . 7

9 . 2

1 3

8 . 5

10-5 3 . 1

4 . 2

4

1 2 . 1

9

9 . 4

9 . 5

1 1 . 3

1 2

9 . 4

1 2 . 4

1 1 . 8

4 . 3

4 . 6

5 . a

4 . 6

6 . 3

9 . 1

3

6 . 6

1 1 . a

1 0 . 6

4 . 3

5 . 7

8 . 4

9 . 6

3 . 7

4

5

5 . 6

1 3 . 3

8 . 4

1 1 . 7

20 . 4

23 . 2

22 . 9

1 0 . 3

1 1

1 1 . 3

1 6 . 5

6 . 4

1 0 . 5

1 3 . 8

1 4 . 7

1 3 . 2

1 1 . 2

1 0 . 4

Ere I

dB

-2 . 2

-0 . 8

- 1 . 1

o . a

-0 . 4

- 0 . 3

- 0 . 2

o . s

0 . 8

- 0 . 3

0 . 5

0 . 2

-2 . 8

- 2 . 3

-2 . 5

-2 . 4

0 . 2

-0 . 8

- 0 . 4

1 . 2

0 . 3

- 1 . 3

1 . 9

-2 . 4

- 2 . 4

1 . 3

- 1

0 . 3

- 1 . 5

-0 . 8

- 2 . 2

-2

-o . 5

- 1 . 4

- 1 . 6

2

2

o . 1

0 . 6

1 . 3

0 . 9

0 . 1

2 . 6

2 . 6

4 . '1

4 . 8

1 . 9

0 . 1

- 1 . 2

- 0 . 8

0 . 4

0 . 4

0 . 4

- 2 . 1

- 0 . 4

-0 . 1

2 . 2

3 . 3

0 . 6

2 . 5

1 . �

- 2 . 8

- 0 . 4

- 0 . 3

2 . 6

-o . a

- 1 . 2

- 1

- 1 . 3

-2 . 1

-2 . 5

1 . 4

Erel

dB

-2 . 2

-0 . 8

- 1 . 1

0 . 8

-0 . 4

-0 . 3

-O t 2

0 . 5

0 . 8

-0 . 3

0 . 5

0 . 3

-2 . 5

-2 . 2

0 . 2

-o . a

-0 . 4

1 . 2

- 1 . 5

1 . 9

-2 . 1

-:? . 6

- 1

0 . 3 - 1 . 4

-o . a

- :? . 3

- 1 . 9

0 . 1

0 . 6

2 . 2

0 . 2

0 . 1

2 . 5

4 . 9

4 . 9

1 . 1

-o . 8

:! . 1

3 . 8

0 . 5

2 . 6

1 . 3

- 1

-1 . 3

::.! . 1

- 2 . 4

Table 5-2 . Table of characteristic values of the regression lines from all measuring series with 64 patients .

(For legends see Table 4-3 . )

Ill ci iii z E c � Ill Ill

� � ., � ., �

:l 3 •I •I 4 6 7 e1 8 9 9

J.O 1 0 1 0 J J l .l 1 ";)

1 2 1 3 14 1.4 1 5 1 5 1 6 1 8 1 8 1 9 1 9 1 9 20 20 :! 1 2 1 :! 3 2 3 :!4 :!4 25 :!5

v v v v v v v v v v v v v v v v v M M M M M v v M 1'1 M M M v v v v v M M M M v v M M

:!6 v 26 v :!7 v 27 v 28 1'1 29 v 29 v 30 v 30 v 3 1 11 3 1 11 3 2 11 32 11 33 11 :13 M 3 3 M 3 4 M 3 4 M 3 4 M 3 4 M 3 5 v 3 6 M 3 6 M 3 7 v 38 v 3 8 v :19 M 3 9 M 4 0 M 4 0 M 4 1 M 4 1 M 4 2 v 4 2 v 4 3 M 4 4 v 4 4 v "" v 45 v 45 v 4 6 v 4 6 v 4 7 v 4 7 v

4 8 M 48 M 4 9 M 4 9 M 50 M 5 1 M 5 1 M 52 v 5 2 v 53 v

54 v

54 v 54 v 5 5 v 55 v 56 v 5 6 v 57 v 58 M 58 M 58 M 5 9 v 60 v 6 0 v 6 1 M 6 1 M 6 2 v 6 3 v 6 3 v 6 4 M 6 4 M 6 5 t1 6 6 M 6 7 M

Cit • -c 0 E l .! .E

0 0

() " 0 " 9 0 0 0 3 0

24 0 "

1 5 0

24 0

1 9 0 0 6 0

0 0

2 J 0 4

1.J. 0

1 4 0 4 ()

1 2 0

13 0

1 3

Cit c 0 ; ca c 0 • Q. 0 ci z

25 1 7 3 1. 6 1 3 .1 4 J 72 1 7 so 35 36 2 4 2 ! 4 6 37 3 2 4 3 33 32 4.! 35 26 72 2 7 4 4 2 7 32 16 44 52 54 45 5 1 53 3:.! 43 3 1 3 6

4 0 44 2 4

l) 4 .. , 1 4 3 9

0 54 13 63

0 56 0 35

21 4 :' 0 5 1

J 4 33 0 48

1 4 52 0 58

13 35 0 36

18 2� 7 23 0 28 1 46 2 81 8 65 0 26 0 53

1 3 49 0 55 0 4 1

1 7 3 6 0 37

17 27 0 38

1 7 49 0 26

14 26 0 30

13 4 6 0 5 1 0 4 2 2 6 0 9 6 8 0 3 9

1 1 4 0

0 4 2 1 2 55

0 45 7 60 0 37

1 2 4 7 0 39

12 59 0 1 1 0 4 6

1 0 6 1 0 58

11 30 0 60 0 40 9 59

1 2 39

0 52 1 1 69

0 55

15 22 0 32 0 76 8 38 2 53 0 36 0 50 3 43 0 so 7 25 0 48 0 24

2 7 20 0 4 6 3 4 2 0 4 4 0 1 6 0 2 6

Intensity­range

dB

t.t0 aJ o l. oO 64 -(,J 6:0 6 :•

6 ':! 6 1 -63 -6 4 57 -38 -62 -6 0 6 0 -6 1 -6 2 6 5 -t.l -

62 -63 -62 -72 -t.l -6 5 73 -63 -68 -611 -65 -70 -75 -64 -64 -65 -63 -66 -

59 -69 -70 -

7 0 76 81 0 5 9 5 80 90 9{, 78 84 88 88 7 8 t.S 9 3 9 7 9 2 8 5 9 3 8 0 9 3 80 74 9{, 9 0 9 4 8 5 80 8 7 7 0 8 7 85 8 6 9 4 9 3 8 3 8 7 76 9 1 8 7 9 2 8 9

6 5 - 9 5 70 - 88 65 - 9 2 60 - 93 6/ - 9 7 6 4 - 8 1

65 - 8 9 63 - 9 1 70 - 88 63 - 88 65 - 9 1 63 - 9 0 69 - 90 71 - 88 63 - 8 1 6 4 - 8 1 6 :'i - 9 0 6 2 - 9 1 6 0 - 9 1 60 - 95 65 - 83 67 - 86 57 - 93 60 - 95 64 - 9 0 6 1 - 85 72 - 85 60 - 7 4 63 - 95 61 - 88 62 - 92 60 - 87 62 - 8 9 6 4 - 9 4 6 5 - 98 67 - 89 64 - 88 6 1 9 l 7 0 - 9 2 £.2 - 82

6 5 - 79 69 - 88 6 1 - 9 0 54 - 94 63 - 88 61 - 8 7 6 1 - 85 59 - 93 73 - 77 64 - 88 59 - 8 7 6 2 - 88 60 - 9 1 6 4 - 9 5 64 - 92 61 - 1 0 1 6 1 - 88 64 - 1 0 2 6 0 - 9 3 70 - 88 68 - 8 7 6 2 - 8 3 58 - 9 4 6 0 - 9 7 6 1 - 1 0 2 6 1 - 97 61 - 85 58 - 85 65 - 9 4 73 - 96 59 - 9 7 6 1 - 80 68 - 80 65 - 95 60 - 93 6 1 - 8 1 5 9 - 80 6 3 8 2

dB

.:. 9 o'J . 5 7 J. 7 2 . 5 7 9 . 5 7 1 . 5

77 . �

7 9 70 75 . 5 7 5 . 5 7 6 o 7 . 5 5 1 . 5 7 7 . 5 8 2 . 5 76 73 77 . 5 7 2 . 5 80 71 6 8 , 5 7 9 8 1 8 0 . 5 7 5 a o . s 7 5 7 3 7 8 7 5 7 8 84 . 5 7 8 . 5 7 3 . 5 7 6 6 9 . 5 7 8 . 5

7 3 80 . 5 79 . 5

8 0 79 78 . 5 76 . 5 8';! 7 2 . 5

7 7 T 7 79 7 5 . 5 78 7 6 . 5 79 . 5 79 . 5 7 2 72 . 5 7 7 . 5 76 . 5 7 5 . 5 7 7 . 5 7 4 76 . 5 75 77 . 5 77 73 78 . 5 6 7 79 7 4 . 5 77 7 3 . 5 75 . 5 79 8 1 . 5 78 76 76 8 1 72

72 78 . 5 75 . 5 74 75 . 5 7 4 73 76 7 5 7 6 7 3 7 5 75 . 5 7 9 . 5 78 8 1 74 . 5 8 3 76 . 5 79 77 . 5

76 78 . 5 8 1 . 5 79 73 7 1 . 5 79 . 5 8 4 . 5 7 8 70 . 5 74 80 76 , 5 7 1 6 9 . 5 7::! . 5

b

xl0-2 0 . 62 1 0 . 054 1 . 06 4 o . so�1 0 . :!4 3 .! . 6 9 1 ! . 0.:!2 0 . 423 1 . :!4 9 0 . 63 6 1 . 06 8 1 . o:n 2 . 273 1 . 6

-,) , 058 0 . 3 1 0 . 26 0 . 867 0 . 559 1 . 796 0 . 432 0 . 054 2 . 1 6 6 0 . 423 0 . 7 4 4 1 . 0 1 1 0 . 73 4 0 . 4 4 1

-0 . 95 7 2 . 1 5 1 0 . 1 85 2 . 004 0 . 475 0 . 258 0 . 57 8 0 . 5 97 0 . 4 20 1 . 1 06 0 . 643

3 . 2 4 4 0 . 85 3 1 . 596

0 . 77 2 . 74 0 . 374 1 . 02 3 0 . 6 1 5 2 . 80 3

- 0 . 3 0 4 1 . 69 8 2 . 00 3 1 . 53 4 1 . 1 76 1 . 5

- 0 . 53 9 0 . 55 1 . 4 6 1 0 . 357 0 . 1 4 4 1 . 1 0 5 1 . 6 2 7 1 . 6 1 5 0 . 256 1 . 27 9 1 . 1 1 7 1 . 5 3 9 0 . 74 0 . 6 4 2 1 . 925 0 . 86 ::!

- 0 . 20 4 1 . 4 3 4 2 . 1 2 1 . 932 1 . 1 1 2 1 . 6 1 5

-0 . 52 4 0 . 936 1 . 1 74

0 . 66 9 - 1 . 079 - 1 . 25

2 . 079 0 . 968 1 . 59 6 1 . 09 7 2 . 088 1 . 1 6 5 1 . 08 3 2 . 27 2 . 4 5 6 1 . 9 2 6 1 . 23 2 3 . 458 1 . 6 2 0 . 7 6 7

- 0 . 3 4 3 1 . 90 4 1 . 1 3 4 0 . 7 7 4 1 . 8 1 2 1 . 28 :!

- 0 . 6 3 8 1 . 384 1 . 55 9 1 . 23 1 . 42 8 0 . 29 9 1 . 1 79 1 . 04

-0 . 3 48 - 0 . 07

0 . 96 1 0 . 96 7 0 . 20 6 0 . 70 6 1 . 27

- 0 . 255 0 . 26 2 . 84 6

AIR FLOW RATE

a

2 . 00 -1 2 . 598 2 . 079 1 . 9 1 3 :! . 1. 9 0 . 36 7 1 . 67 2 . 053 1 . 593 :! . 2 4 7 1 . 726 1 . 457 1 , 0 1 6 2 . 0 1 3 2 . 632 2 . 4 1 1 2 . 34 2 1 . 9 1 6 2 . 06 4 0 . 93 1 1 . 6 4 7 2 . 4 4 9 0 . 1 8 3 2 . 053 1 . 73 4 3 . 355 3 . 24 2 . 205 3 . 084 0 . 76 4 1 . 976 0 . 755 2 . 09 2 . 46 3 2 . 1 7 2 . 96 2 . 0 1 1 2 . 1 5 1 2 . 0 1 7

- 0 . 072 1 . 7 9 1 0 . 937

1 . 7 1 0 . 072 1 . 642 1 . 407 1 . 88 1 4 . 4 1

2 . 686 1 . 293 0 . 87 4 0 . 988 1 . 364 1 . 249 2 . 58 9 1 . 933 0 . 9 9 7 1 . 7 3 '1 2 . 62 2 1 . 829 1 . 3 1 8 1 . 32 5 2 . 086 l . 4 7 1 1 . 54 1 . 0 1 4 1 . 63 1 . 698 0 . 7 7 6 1 . 84 7 2 . 6 7 9 1 . 34 1 . 0 1 5 1 . 09 1 1 . 83 6 1 . 2 1 6 2 . 74 1 . 9 4 1 . 76 9 1 . 96 1 3 . 27 8 3 . 28 9

0 . 79 1 1 . 39 2 1 . 048 1 . 42 3 0 . 609 1 . 35 2 1 . 6 4 6 0 . 6 4 4 0 . 469 1 . 205 1 . 6 1 8

-0 . 1 1 8 1 . 25 6 1 . 63 4 2 . 6 5 6 0 . 933 3 . 35 2 . 06 7 1 . 0 1 9 2 . 00 4 3 . 1 0 2 3 . 1 1 . 32 7 1 . 32 1 1 . 24 4 1 . 7 7 1 1 . 708 1 . 66 1 2 . 83 4 '2 . 43 1 . 55 9 1 . 94 2 . 32 1 . 8 96 1 . 45 1 2 . 702 2 . 393 0 . 1 5 8

e.s.d.e.

0 . 05 o . u Q , 1 7 0 . 1 2 0 . 1 2 0 . 0 6 o . 0'7 o . o8 0 . 0 7 o . o8 0 . 1 0 . 09 0 . 1 0 . 1 0 . 1 5 0 . 09 o . 1 9 0 . 08 o . oo o . ot, 0 . 1 1 0 . 1 1 0 . 26 0 . 08 0 . 1 0 . 1 ? 0 . 1 0 . 1 3 0 . 07 0 . 08 o . o8 0 . 1 1 O . J. 0 . 1 0 . 09 0 . 1 1 O . l. 5 o . o8 0 . 1 3

0 . 1 6 0 . 1 1 0 . 1 1

0 . 09 0 . 1 0 . 1 4 0 . 1 0 . 0 7 0 . 1 8

o . o8 0 . 1 6 0 . 1 3 0 . 1 1 0 . 08 0 . 1 1 0 . 1 1 0 . 09 0 . 09 0 . 1 6 o . J 1 0 . 07 0 . 1 9 0 . 1 7 0 . 1 3 0 . 1 5 0 . 1 3 0 . 24 o . o8 0 . 1 0 . 06 o . o8 0 . 1 2 0 . 1 3 0 . 06 0 . 1 6 0 . 07 0 . 06 0 . 1 5 0 . 1 6 0 . 1 1 0 . 2 0 . 1 0 . 1

0 . 09 o . o8 0 . 1 3 0 . 1 4 0 . 1 0 . 1 2 0 . 09 0 . 1 1 0 . 04 0 . 09 0 . 1 4 0 . 1 6 0 . 1 1 0 . 08 0 . 1 2 0 . 22 0 . 23 0 . 1 1 0 . 09 0 . 05 0 . 1 0 . 1 4 0 . 1 1 0 . 06 0 . 1 0 . 1 8 0 . 1 4 0 . 1 8 0 . 1 2 0 . 06 0 . 1 2 o . os 0 . 1 3 0 . 1 3 o . 1 5 0 . 04 0 . 06 0 . 1

ml/s

4 3 2 <• 8 1 1 7 4 �42 1 96

�'70 244 293 534 3 4 1 1 7 4

355 688 JOt. 464 34t. 354 3 1 4 1 7 1

98 307

4 6 244 2 1 7 348 489 364 232 2 1 6 1 3 2 1 f:l 1 289 1 7 6 420 332 2 1 7 832 333

1 97 300 l. 6 l.

2 1 ::! 1 7::!

86 155 24J :'39

283 3 9 9 286 1 4 0 1 9 1 2 4 9 1 45 234 11 2 1 00 5 4 1 4 7 2 352 377 1 8 8 2 8 1 2 3 9 1 6 1 1 58 1 4 7 1 9 4 :! 6 6 3 2 9 256 444 324 474 3 1 0 206 468 459 295 254 244

1 9 4 1 4 2 1 79 1 7 2 1 53 1 6 4 273 234 205 467 329 299 302 175 245 299 320 5 1. 2 254

1 039 406 1 2 5 3 2 5 1 9 3 256 1 0 2 370 254 36 1 235 204 4 1 8 2 9 7 2 8 9 2 6 5 332 375 167

b

xl0-2 1 . 6 2 7 0 . 6 74

-0 . 20 9 2 . 07 2 . 704 0 . 4 2 1 t . 963 1 . 728 L . 726 1 . 678 1 . 37 :! . 797 4 . 28 1 2 . 092 1 . 1 1 4 1 . 6 3 1 1 . 3 7 8

2 . 3 3 1 1 . 94 3 J . 1 3 4 1 . 879 3 . 6 2 7 0 . 6 9 1 . 728 2 . 4 56 1 . 79 1 . 83 1 1 . 867 2 . 1 9 8 0 . 7 1 7 2 . 774 2 . 9 7 7 1 . 44 8

- 0 . 03 3 2 . 38 3 1 . 6 06 1 . 83 7 0 . 34 2 . 3 4 8 2 . 433 2 . 883 1 . 58

1 . 84 2 3 . 855 1 . 948 2 . 6 1 8 2 . 66 9 2 . 4 4 :! 1 . 06 9 2 . 398 2 . 4 1 9 1 . 9 24 2 . 1 86 2 . 90 6 2 . 04 4 1 . 1 0 3 1 . 592 1 . 927 1 . 9 1 6 1 . 65 2 2 . 1 3 2 . 1 9 9 2 . 57 9 1 . 56 9 1 . 1 1 1 2 . 269 1 . 05 1 2 . 08 3 2 . 802 1 . 903 1 . 3'75 1 . 99 2 . 58 2 . 1 4 3 1 . 768 2 . 9 9 7 2 . 303 2 . 7 1 1 2 . 6 72 3 . 0 7 2 2 . 286 2 . 1 5 7

3 . 35 6 2 . 4 4 6 2 . 1 5 7 1 . 4 25 2 . 758 2 . 6 3 7 2 . 75 9 3 . 2 4 8 2 . 73 1 2 . 2 5 8 2 . 684 1 . 86 7 1 . 66 2 1 . "l7 1 2 . 1 7 6 1 . 76 8 2 . 33 1 2 . 98 1 . 4 72 1 . 9 0 . 89 1 2 . 37 1 2 . 5 2 . 079 3 . 1 3 7 1 . 04 1 . 085 1 . 3 1 1 . 7:!8 2 . 1 1 3 3 . 778 1 . 537 2 . 29 2 . 56 2 2 . 655 0 . 55 3 0 . 899

SUBGLOTTIC PRESSURE

a

0 . 92 () , 47fl 0 . 1 3 6

- :1 . 696 2 . 1 74 0 . 4 1 1

- 1 . 627 - 1 . 488 - 1 . 385 - 1 . 204

0 . 9 1 4 -2 . 1 7 8

2 . '752 - 1 . 34 7 - 0 . 78 9 - 1 . 092

1 . 058 - 1 . l 1 6 - 1 . 46 5 - 0 . 548 - 1 . 303 - 2 . 73 1 -0 . 58

1 . 4 88 - 1 . 5 7 - 1 . 382 - 1 . 265 - 1 . 3 4 1 - 1 . 6 7 2

0 . 604 - 2 . 1 5 6 -2 . 24 2 - 1 . 085

0 . 205 - 1 . 804 - 1 . 069

1 . 435 -0 . 1 3 7 - 1 . 794 - 1 . 869 - 1 . 99 9 - 1 . 094

-1 . 46 7 -2 . 958 - 1 . 6 1 - 1 . 982 -2 . 1 73 - 1 . 953 - 1 . 026

1 . 90 1 ::! . 002

- 1 . 4 4 2 1 . 705

- 2 . 024 - 1 . 6 1 9 - 0 . 425

0 . 9 9 7 - 1 . 293 - 1 . 4 74 - 1 . 232 - 1 . 78 - 1 . 74 1

- 0 . 99 5 -0 . 86 1 - 1 . 923 - 1 . 5 3 1 - 1 . 6 7 -:! . 025

1 . 39 -0 . 979 - 1 . 4 43 - 1 . 98

1 . 7 4 1 - 1 . 24 3 -2 . 4 1 8 - 1 . 89 1 - 2 . 036 -2 . 04 2 -2 . 385 - 1 . 90 7

1 . 783

-0 . 755 -2 . 552 - 1 . 8 1 5 - 1 . 797 - 1 . 0 1 4 -2 . 09 7 - 2 . 097 - 2 . 2 7 6 -2 . 5 45 - 1 . 93 - 1 . 63 9 -2 . 0 7 - 1 . 56 2 - 1 . 23 7 - 1 . 4 77 - 1 . 56 2 - 1 . 276 - 1 . 72 4 -2 . 263 - 1 . 22 - 1 . 282 -0 . 504 - 1 . 986 -2 . 1 73 - 1 . 777 -2 . 54 2 -0 . 4 2 8 - 0 . 6 4 4 -0 . 9 1 6 - 1 . 33 5 - 1 . 756 - 2 . 832 - 1 . 20 1 - 1 . 8 1 2 -2 . 004 - 1 . 885

0 . 2 1 7 - 0 . 503

e.s.d.e.

0 . 08 0 . 1. 7 0 , 09 () , ()9 0 . 07 o . oJ o . o8 0 . 07 0 . 06 o . o8 () , ()9 o . J 0 . 1 1 0 . 1 0 . 1 8 o . :13 0 . 07 0 . 1 2 0 . 08 0 . 03 0 . 1 0 . 09 0 . 1 6 0 . 07 0 . 1 6 0 . 1 0 . 0 7 0 . 1 0 . 1 2 0 . 0 7 0 . 06 0 . 1 1 0 . 08 o . os 0 , 1 0 . 1 1 0 . 09 0 . 09 o . 1 2 o . 1 3 0 . 09 0 , 1 4

0 . 1 1 0 . 1 2 0 . 0 7 0 . 1 4 0 . 1 0 . 1 1 0 , 1 1 0 . 1 0 , 1 0 . 1 1 o . o�� 0 . 1 1 0 . 1 2 0 . 1 1 0 . 06 0 . 09 0 . ()9 0 , 1 0 . 1 0 . 1 2 0 . 07 0 . 07 0 , 06 0 . 1 0 , 09 0 . 1 o . o8 0 . 06 o . o8 o . 1 2 0 . 1 0 , 1 0 . 1 5 0 . 1 1 0 . 1 3 0 . 06 o . o8 0 . 1 6 0 . 07 o . o8

0 . 1 2 0 . 1 5 0 . 1 1 0 . 1 0 . 1 2 0 . 1 5 0 . 1 3 0 . 1 6 o . o8 0 , 09 0 . 1 6 0 . 1 1 0 , 1 4 0 . 09 0 . 0 7 0 . 1 5 0 . 1 4 0 . t 1 0 . 09 0 . 08 0 . 1 4 o . o8 0 . 1 1 0 . 1 0 . 1 1 0 . 1 0 . 1 0 . 1 5 o . oe 0 . 09 0 . 1 1 0 . 1 3 0 . 1 5 0 . 1 3 0 , 1 1 0 . 1 1 0 . 1 2 0 , ()4

kPa

1 . 59 () , 98 0 . '1 7 0 . 64 0 . 95 0 . 78 0 . 7 FJ 0 . 75 0 . 67 1 . 1 5 1 . 32 o. 8'1 o . A 7 0 . 54 1 . 1 9 ! . A 0 . 98 0 . 97 1 . 1 1 . 88 1 . 58 0 . 7 0 . 78 0 . 75 2 . 63 1 . 1 4 1 . 28 1 . 45 0 . 95 0 . 83 1 . 02 0 . 98 1 . 1 1 1 . 5 1 . 1 7 1 . 29 0 . 92 1 . 26 1 . 1 2 0 . 8 1 2 . 1 1 . 45

1 . 0 1 1 . 22 0 . 83 1 . 05 1 . 04 0 . 66 0 . 63 o . 88 0 . 8 1 1 . 02 1 1 . 58 1 . 0 1 2 . 8 3 1 . 4 1 1 . 2·7 1 . 03 1 . 08 0 . 67 0 . 92 0 . 72 1 . 6 0 . 94 0 . 69 0 , 79 0 . 7 1 1 . 5 0 , 77 1 . 33 1 . 1 1 . 02 0 . 68 1 . 2 4 0 . 89 0 . 97 1 . :! 0 . 97 0 . 89 0 . 88 0 . 59

0 . 9 2 t . 2 1 1 . 08 0 . 63 1 . 1 5 o . 88 0 . 67 0 . 66 0 . 78 1 . 4 1 . 02 0 . 88 0 . 7 1 . 2 1 0 . 96 1 . 59 1 . 1 1 . 62 1 . 0 4 O . fl8

1 . 39 0 . 65 0 . 6 2 0 . 83 0 . 86 2 . 1 5 1 . 35 1 . 3 4 1 . 33 0 . 78 0 . 68 0 . 86 1 . 05 0 . 9 1 3 . 99 1 . 4 1

b

xl0-2 7 . 75 1 9 . 272 9 . 1 4 5 7 . 3 4 2 7 . 052 6 . 889 7 . 0 1 5 7 . 8 4 9 7 , 0 25 7 . 605 7 . 56 2 6 . 1 7':! 3 . 4 4 7 6 . 308 a . '?45 8 . 059 8 . 36 3 6 . 80 2 7 . 49 7 7 . 07 7 . 689 6 . 3 1 9 7 . 1 4 3 7 . 84 9 6 . 8 9 . 22 1 8 . 903 7 . 69 2 8 . 75 9 7 . 1 3 2 7 . 0 4 5 . 0 1 9 8 . 078

1 0 . 29 1

7 . 04 8 . 99 1 7 . 735 a . sss 7 . 009 4 . 32 4 6 . 265 6 . 824

7 . 388 3 . 406 7 . 678 6 . 359 6 . 7 l. 5

1 0 . :1 6 1 9 . 235 5 . 904 5 . 578 6 . 5 4 3 6 . 639 5 . 595 8 . 495 8 . 348 6 . '146 7 . 7 1 6 7 . 94 7 . 24 3 6 . 24 3 (, . 1 8 6 7 . 1 6 5 7 . 1 5 2 7 . T7 1 6 . 1 9 2 7 . 408 6 . 77 2 5 . 2 7 3 7 . 1 7 9 8 . 808 6 . 57 6 5 . 3 5 . 9 25 7 . 1 1 9 5 , 389 8 . 22 1 6 . 35 2 6 . 1 5 3 6 . 25 9 8 . 793 9 . 093

6 . 92 5 . 675 5 . 958 6 . 74 6 6 . 4 8 7 6 . 077 6 . 28 4 . 97 1 4 . 292 5 . 3 4 2 6 . 50 9 J . 858 6 . 5 1 3 7 . 57 1 8 . 472 5 . 92 9 . 366 6 . 895 5 . 208 7 . 24 6 8 . 7 3 7

1 0 . 4 92 6 . 07 6 . 27 6 . 493 6 . 56 4 7 . 78 7 . 875 9 . 038 8 . 3 4 2 6 . 926 5 . 254 8 . 25 6 7 . 004 6 . 1 6 7 7 . 6 9 . 1 86 6 . 254

EFFICIENCY

a

-6 . 00·1 - 6 . 962 - 7 . 055 -4 . '7 58

4 . 85 7 -4 . 798

4 . 1384 -� . 4 06

5 . 04 9 -5 . 883 - 5 . 653 -4 . 1 2

2 . 905 -5 . 507 - 6 . 683 -6 . 1 6 -6 . 1 25 - 5 . 0 4 1 - 5 . 4 4 - 5 . 224 - 5 . 1 8 5 - 4 . 559 -4 . 44 4 -·5 . 406 - 5 . 00 6 -(, , 8 1 3 - 6 . 8 1 6 - 5 . 705 -6 . 253 -5 . 00 1 - 4 . 66 - 3 . 354 - 5 . 84 6 - 7 . 50 9 - 5 . 207 - 6 . 73 2 - 5 . 4 1 7 - 6 . 856 -5 . 06 4 -2 . 9 -4 . 63 4 - 4 . 684

-5 . 084 - 1 . 955 - 4 . 97 2 - 4 . 26 6 ··- 4 . 548 -7 . 298 -6 . 50 1

...: 4 . 232 -3 . 71 3 -4 . 387 -4 . 5 -4 . 06 6 -5 . 8 1 1 -6 . 34 9 - 4 . 84 1 -5 . 28 7 - 5 . 98 9 - 5 . 438 - 4 . 3 7 9 - 4 . 425 -4 . 87 7 - 5 . 3 1 7 -5 . 52 - 3 . 9 3 2 -4 . 94 - 4 . 53 3 -3 . 59 2 -5 . 258 - 6 . 54 1 -4 . 7 3 9 -3 . 876 -4 . 1 9 1 - 5 . 4 3 4 -3 . 63 9 -5 . 69 - 4 . 74 5 -4 . 568 - 4 . 4 1 7 -6 . 2 1 2 -6 . 34 6

- 4 . 8 76 -3 . 68 - 4 . 073 - 4 . 467 -4 . 4 3 5 -4 . 096 -4 . 39 -3 . 208 -2 . 7 6 2 - 4 . 1 1 5 -4 . 82 -2 . 65 3 - 4 . 536 -5 . 238 -6 . 02 1 - 4 . 2 1 1 -6 . 9 1 5 - 5 . 1 8 4 - 3 . 596 - 5 . 6 2 6 -6 . 66 - 7 . 4 3 6 - 4 . 1 8 1 - 3 . 988 - 4 . 308 - 4 . 07 -6 . 1 2 1 - 5 . 8 5 8 - 6 . 759 - 5 . 936 -4 . 64 4 -3 . 948 -5 . 959 -4 . 925 -4 . 288 - 5 . 658 - 7 . 4 5 1 -4 . 496

e.s.d.e.

0 . 1 1 0 . 26 0 . 1 7 0 . 1 9 0 . 1 8 0 . 06 0 . 1 0 . 1 0 . 1 t 0 . 1 0 . 1 5 0 . 1 5 0 . 1 8 0 . 1 4 0 . 2 0 . 4 2 0 . 22 0 . 1 7 0 . 1 5 0 . 07 0 . 1 2 0 . 1 5 0 . 2 1 0 . 1 0 . 1 1 0 . 2 1 0 . 1 2 0 . 1 1 0 . 1 4 0 . 09 0 . 1 0 . 1 3 0 . 1 4 0 . 1 0 . 1 5 0 . 1 7 0 . 1 0 . 1 2 0 . 2 0 . 24 0 . 1 4 0 . 2

0 . 1 8 0 . 1 8 0 . 1 5 0 . 1 9 0 . 1 5 0 . 1 9 0 . 1 6 0 . 2 1 0 . 1 8 0 . 1 2 0 . 1 2 0 . 1 8 0 . 1 7 0 . 1 4 0 . 1 2 0 . 2 1 0 . 1 1 0 . 1 4 0 . 25 0 . 2 1 0 . 1 4 0 . 1 6 0 . 1 4 0 . 28 0 . 1 5 0 . 2 0 . 1 2 0 . 1 1 0 . 1 4 0 . 1 6 0 . 1 3 0 . 1 9 0 . 2 1 0 . 1 5 0 . 1 8 0 . 1 9 0 . 1 5 0 , 3 0 . 1 2 0 . 1 2

0 . 1 5 0 . 1 9 0 . 2 0 . 2 0 . 1 7 0 . 2 1 0 . 1 8 0 . 1 7 0 . 1 1 0 . 1 6 0 . 1 8 0 . 1 7 0 . 1 9 0 . 1 2 0 . 1 3 0 . 34 0 . 35 0 . 1 9 0 . 1 2 0 . 1 3 0 . 2 0 . 1 9 0 . 1 4 0 . 1 3 0 . 1 5 0 . 1 9 0 . 2 0 . 28 0 . 1 8 0 . 1 3 0 . 1 5 0 . 1 4 0 . 26 0 . 1 9 0 . 1 9 0 . 1 1 0 . 1 3 0 . 1 1

xl0-5 0 . :::! 0 . �� 0 . 3 2 . 3 5 . 6 1 . �' 3 . 6

6 . 2 0 . 7 o . 8 1 . 1 3 . 7 0 . 3 0 1 . 8 3 . 1 1 . 7 0 . 8 2 . 3 o . 8 9 , 3 o . 8 2 . 8 6 . 2 3 . :! 4 . 1 0 . 7 3 . 1 2 . 1 1 . 6 6 . 8 2 . 6 2 . 8

1 5 . 4 2 . 1 o . e 2 . 9 0 . 1 2 . 7 1 . 8 2 . 6 5 . 5

6 . 7 5 . 4

1 4 . 3 " 9 . 1 1 . 6 4 . 1

2 . 1 4 . 9 3 . 6 4 . 8 1 . 6 8 . 8 1 . 9 1 . 4 2 1 . 5 1 . 3

2 7 . 3 5 . 8 2 . 6 3 . 5 0 . 4 2 . 6 1 . 4 1 . 6 1 . 5 0 . 9 4 . 1

1 0 . 3 1 . 6 1 . 3

8 . 1 1 . 6

1 . 3 6 2 . 7 3 . 4 2 . 9 2 . 5 1 . 6 3 . 7 2 . 9 0 . 9 0 . 9 1 . 7 2 . 4 6 3 , 9 3 . 8 1 . 2 3 . 5 2 . 4 1 . 3 1 . 3 1 . 5 2 . 7 8 . 6 9 . 6

1 3 0 . 4 0 . 6 2 . 7

1 3 5 . 7 0 , 6 1 . 4 4 . 8 2 . 7 o . s 0 . 1 1 . 1

dB

9 . 1 -8

9 . 4 - 1 . 1

1. . 7 - .:? . 8

2 . 4 0 . 9

-4 . 5 -7 . 4 -6 . 1 - 1 . 3 - 7 . 3

- 1 4 - 5 . 4 - 6 . 2 - 4 . 7 -5 . 8 -4 . 2 -5 . 7

0 . 2 -4 . 5

2 . 3 - 0 . 9 - 5 . 1 -3 . 7 - 7 . 7 -5 -3 . 2 - 3

0 . 1 - 2 . 2 - 3 . 7 -o . s -5 . 4 -6 . 6 - 2 . 3

- 1 1 . 9 -4 . ':! -2 . 5 - 5 . 7 - 1 . 8

- 1 . 2 - l . S

3 - 1 . 3 - 1 . 2 - 2 . 6 - 1 . 5

- 4 . 5 - 1 . 9 - 1 . 1 - 1 . 4 -5 . 1

0 . 2 -6 . 3 -:.! . � - i • -6 . 3 -6 . 3 -3 . 3 - 4 . 2 - 1 . 4 -5 . 7 -3 . 2

0 . 7 0 . 1

- 0 . 9 -3 . 1 -5 . 7 - 4 . 7 -4 . 4 -5 . 5 - 3 . 7 - 7 . 2 - 2 . 7 - 0 . 3 -6 . 1 - 5 . 9 -3 . 6 - 1 -2 . 4

-3 . 4 - O . A -2 . 4 - 0 . 4 -2 - 1 . 7 - 3 . 1 - 1 . 3 - 1 . 8 - 7 . 5 -5 . 7 -3 . 9 -:::! . 8 - 1 . 4 - 2 . 3 - 4 . 3 -5 . 4 -6 - 3 . 4 -7 . 9 -6 . 8 -3 -2 . 6

o . 8 - 0 . 6

2 . 3 - 9 , 5 - 6 . 4 - 4 . 9 - 1 . 2 - 0 . 6 -5 . 9 -4 . 2 -2 . 7 - 3 -6 . 4

- 1 3 . 5 -4 . 3