Dept. for Speech, Music and Hearing

Quarterly Progress andStatus Report

Laryngeal articulationstudied on Swedish subjects

Lindqvist-Gauffin, J.

journal: STL-QPSRvolume: 13number: 2-3year: 1972pages: 010-027

http://www.speech.kth.se/qpsr

STL-QPSR 2-3/1972 ?

B. LARYNGEAL ARTICULATION STUDIED ON SWEDISH SUBJECTS

J . Lindqvist

Abstract

This paper descr ibes some observations of laryngeal adjustments during speech by means of a f i b e r s c ~ p e inserted through the nasal t ract . Special attention has been paid to laryngeal articulation for consonants,for pitch con- trol , and for morpheme boundary marking.

Introduction

The larynx plays the pr imary role in modulating and regulating the flow

of a i r delivered by the subglottic system thus providing the basis for speech

sound production. This is brought about by different laryngeal gestures ,

superimposed on the speech posture of the larynx. In analogy with ora l a r -

ticulation we re fe r to these gestures a s laryngeal articulation. Several

techniques have been applied to study laryngeal articulation in connected

(1) speech . Owing to the grea t difficulties associated with measurements

of laryngeal activit ies most methods used have been indirect, such a s t rans- I

1 illumination of the glottis(2) for optical measurements of the variation in the I

glottis a r e a and electr ical glottography which i s 2n electr ical impedance 1 1 measurement a c r o s s the larynx(3). X-ray motion pictures (4) and even ul-

(5) t rasonic monitoring of the vibration of thc vocal folds have been t r ied . Although some progress has been made these methods give only indirect

measurements of the laryngeal articulation. More d i rec t measurements of

the activity of the laryngeal muscle s havc been performed by EMG-experi-

ments(6) , which have given valuable information about the function of some

of the intrinsic laryngeal muscles. By the introduction of thin wire -electrodes

this method has been further refined(7) and it i s now one of the most power-

ful tools in laryngeal rescarch . Even if the EMG-signal gives fair ly good

information about the activity of a muscle , i t may sometimes be hard to in-

t e rp re t and a lso to collect the data without some hypothesis about the function

of the larynx in t e r m s of an articulatory model. F o r instance in EMG-ex-

per iments on the larynx the muscles a r e generally identified with reference

to some known function of the muscle and thc position of the electrode is

checked by observing if the expected response i s obtained. Therefore EMG-

data a r e not available for laryngeal mechanisms that a r e l e s s well under - stood such a s the pitch lowering mechanism.

STL-QPSR 2-3/1972 12.

A film speed of 19 to 25 frarnes per sccond was used in this investigation.

The film speed was limited by the available light intensity. F o r most pu r -

poses this fi lm specd i s sufficient but for m o r e accurate measurements on

glottal timing a higher frame ra te i s needed. However, by using optical

glottography together with the fi lm registration, which gives a continuous

registration of the variation in the glottal a r e a , a detailed study of the timing

of the glottal abduction gesture can be made. This technique was used on one

of the subjects by placing; a photo-multiplier tube against the pre- t rachea l

\-?all below the larynx. Some of the light f rom the fiberscope which passed

through the glottis thus reached the photo -multiplier tube transcutaneously.

The diameter of the fiber scope i s 5 m m which made it necessary to se-

lect subjects with a ra ther wide nasal t ract . About every second subject

had to be rejected due to this restraint . Surface anesthesia was applied in

the nasal cavity and the epipharynx beforc the fiberscope was inserted. When

the fiberscope was put in i ts place it did not cause discomfort for most of the

subjects.

P r e -speech articulation

When the larynx is not used for speech, the glottis i s generally quite

open for breathing. When an utterance i s to s t a r t , the vocal folds have to

move f rom this position to the speech posture. The speech posture of the

larynx i s with the vocal folds in voicing position. The time i t takes for this

movement i s about 200 rnsec or more and the maximum speed of the move-

ment i s about the same a s for glottal abduction for voiceless consonants in

s t ressed syllables. The timing of the anticipation of the voicing position i s

generally such that it should be reached a t the beginning of the f i r s t sound,

i r respcct ive of If this sound i s voiced o r voiceless. If the speaker hcsi ta tes

before starting to speak, the speech will generally be preceded by a glottal

stop gesture (I2) so that the subglottal p res su re i s allowed to r i s e before the

speech i s initiated. If this i s not the case thcre must be a careful synchron-

ization of the closing movement and the activity of the resp i ra tory muscles.

If the subglottic p res su re i s increased too la te , the voicing will be delayed

and if it i s increased too ear ly , the speech will s t a r t with an [h]-like a sp i r a - J. - on. The la t ter i s the case for a Swedish dialect(I3), where words with an

initial vowel s t a r t s with an [hl- l ike aspiration. Initial rh] i s instead r e - - placed by a glottal stop. London "cockncy" i s a more familiar example of

( 14) this phenomenon .

STL-QPSR 2-3/1972 13.

P o s t - speech articulation

F r o m our data i t i s evident that an utterance is normally actively t e r -

minated. The re turn of the larynx to the breathing posture i s not made by

a relaxation of the laryngeal muscles. Instead an active command i s used

to terminate the speech and return to thc breathing function. Because the

purpose i s to stop thc voicing a t the end of the phrase this can be done by

onc of the two devoicing gestures of the larynx(15). These a r e the glottal

stop gesture - and the glottal abduction gesture. F o r Swedish speakers the

most common terminator i s the glottal abduction gesture. In the Eskilstuna

dialect ( 16) of Swedish, however, the glottal stop gesture may a lso be used

a s a terminator of speech.

The terminating abduction gesture i s s imilar to the devoicing gesture

used for voiceless consonants with the exccption that the vocal folds do not

close again if speech i s not continued. Instead they stay half -opened for a - I 1 bout 50- 100 m s e c and then opened completely for breathing. Fig. I-B- I , I shows a schematic description of this type of articulation when the utterance

ends with a vowel. Also in the glottographic recordings shown in Figs.

I-B-5 and I-B-8 this terminating abduction gesture can be seen. The vocal

folds continue to vibrate until the peak of the abduction gesture. However,

the amplitude of the acoustic signal i s reduced to a very low level a l ready

in the beginning of the abduction due to the ineffective modulation of the air-

flow when the vocal folds do not close for each vibration cycle. The asp i -

ration caused by the terminating abduction gesture i s mostly too faint to be

pcrceived in speech. If, on the other hand, the sound i s recorded on tape

and played back backwards this aspiration can be heard a s an initial [h].

The Swedish consonant svstem

The Swedish consonant system can be divided into 18 phonemes a s i s

i l lustrated in Table I-B-1. Regarding thc laryngeal condition these phon-

e m e s can be divided into two main groups: the voiced (o r lax) consonants

and the voiceless (o r tense) consonants.

TABLE I-B-1. voiced voicele s s

stops b d g P t k

fricatives v j f s ~ 5 nasals m n r3 liquids r 1

aspirated segment

c Amplitude of speech sound

> Time

End of utterance

Voicing posit ion,

Peak area of vocal fold vibrations

Mean glottal area

Fig. I -B- I. Description of the devoicing gesture used to terminate an utterance.

>

STL-QPSR 2-3/1972 14.

Laryngeal articulaticn for voiced consonants

F o r nasals and liquids the aerodynamic conditions for vocal fold vibra-

tions a r e not very different f rom vowels and there seems to be no reason

to assume different laryngeal conditions for these sounds.

The o ra l constriction used for the production of voiced stops and f r i c -

atives, however, reduces the p res su re drop a c r o s s the glottis considerably

and pos sible mechanisms for maintaining the voicing have been discussed

by Halle and Stevens(''). One of these suggested mechanisms i s an adjust-

ment of the positioning of thc vocal folds by a small abduction gesture in I

o rder to facilitate voicing. However, according to our findings this mech- I

anism should have the opposite effect. (In a more recent paper these authors 1 I

suggest that: "Slackness of the vocal cords can allow glottal vibrations to i I

occlzr even with a spread o r constricted glottis". ) On the optical glottogram

recorded with one of the present subjects a slight separation of the vocal

folds could often be observed towards tllc end of the occlusion of the voiced

stops. Moreover, EMG-experiments made with English speaking subjects

seem to indicate that the activity in the laryngeal muscles i s different for

voiced consonants than for vowels(i8). There a r e a l so other indircct evi-

dence f rom air-flow measurements that there i s an active abduction ge-t u r e

for the articulation of voiced consonants ( I 9 ) . Also d i rec t observations of

the larynx with fibcroptics on English subjects have shown a separation of (20) the arytenoids f o r voiced obstruents .

On the film registrations which a r e reported on in this paper only a few

examples of vocal fold separation for voiced stops have been found. How-

eve r , no arytenoidal adjustment for the production of vciced consonants has

been observed.

An interesting question i s if the observed separation of the vocal folds

i s a passive consequence of the r i s e in intraoral p res su re o r caused by an

activity change in the laryngeal muscles. If the main cause i s a change in

tlle activit ies of the laryngeal muscles , another interesting question a r i se s :

Is this a learned adjustment, such a s a i ~ ~ e c h a n i s m to facilitate voicing, o r

i s it an activity change of a ref lex character with no special function in

speech? This reflex could for instance be a coupling between ora l constric-

tion and glottal abduction with some phylogenetic origin. Maintaining the

voicing position may in that case be an active control. This i s of course

STL-QPSR 2-3/1972 15.

only vague speculations and there a r e no known reasons to assume that this

hypothesis i s true. However, too little i s known about the organization of

the nervous system for the control of the speech organs and rational r e a -

sons, according to the present state of knowledge, may not always be found.

Experiments regarding spontaneous voicing for consonants

In order to investigate these questions further two experiments were

performed with Swedish subjects. In both cxperirnents a valve was inserted

in the subject ' s mouth so that the vocal t r ac t could be closed off by the ex-

per imenter . Maskins noise was used in the subjects' e a r s to prevent a -

coustic feed-back.

When the subject was phonating the valve was closed to simulate a r b] - occlusion, optical glottograms s imilar to +hose for voiced stops in connected

speech could be recorded. When the subject t r ied to re lax the neck mus-

c les , it was possible to observe a deflection of the glottogram indicating a

vocal fold separation slightly above the peal: of the vibration amplitude pr ior

to the closure of the valve, a s seen in Fig. I-B-2. The reaction of the vocal

folds to the increased intra-oral pressurc seems to be much dependent on

the laryngeal conditions and varied both with voice intensity and pitch.

These findings indicate that the state of the laryngeal nluscles i s important,

but the main mechanism behind the observed separation of the vocal folds

seems to be the increased intra-oral p rcs su re during the occlusion.

In a second experiment, the intra-oral p res su re was recorded simulta-

neously with the voicing picked up with a throat microphone during sustained

phonation. By making every other o r every third closure of the valve long

enough to produce complete equilization of the sub- and supraglottal p r e s -

sure the subglottic p res su re could be detcrx~ined. In the recording shown

in Fig. I-B-3 we have assumed that the subglottic p rcs su re was kept con-

stant inbetween the two points were it was determined. In Fig. I-B-3 it

can be seen that the vocal folds could continue to vibrate down to a pressu re

drop of nearly 1 cm H 0. This was found a t low and nol-ma1 fundamental 2 frequency. (For increased fundamental frequency the voicing stapped a t a

higher pressure drop. If the pitch i s high this suggests the possibility of

facilitating voicing by lowering the pitch. ) Even if it should be possible, by

an adjustment of the vocal folds, to maintain voicing to a st i l l lower p re s - sure drop the acoustic resu l t would hardly be perceptible and there should

be no feed-back to enable the learning of this articulation.

Fig. I-B-2. Recordings of sound signal (a) and optical glotto- gram (b) during the experiment described in the text.

Fig. I-B-3. Recordings of the signal from a throat micro- phone (a) and pressure drop across the glottis (b) during the experiment described in the text.

STL-QPSR 2-3/1972 16.

Conclusions

According to the resu l t s obtained by thc two experiments described above

we assume that Swedish voiced stops a r e produced with the vocal folds in

voicing (neutral) position without any adjustments in order to maintain voicing.

Thus the observed movement seems to bc, a t leas t for Swedish, a passive

cor.sequence of the r i s c in intra-oral prcssure .

The maiii factors determining the degrce of voicing for voiced stops a r e

the yielding walls of the vocal t r ac t and the movement of the tongue. It i s

easy to calculate that with completely stiff vocal t r ac t walls the voicing would

stop within one o r two cycles af ter the ora l closure. F o r Swedish it i s not yet

kna-mifthe yielding of the walls is active in the sense that thc muscles a r e

relaxed or activated for that purpose. At leas t for the v e l a r voiced stop [g]

the movement of the tonguc seems to be differently programmed from the

voiceless cognate. Further investigations must be made before this question

can be answered. However, it i s quite c lcar that there must be a fundamental

difference in the articulation of Swedish voiced stops and more audible voiced

stops like those used in, for instance, French and Russian. If our assump-

tion about the laryngeal condition for Swedish voiced stops i s cor rec t , the

cxtra effort in the articulation of the Frcnch and Russian voiced stops does

not serve the purpose of maintaining the voicing but to make it more audible.

This can only be done by increasing the p rcs su re drop a c r o s s the glottis, ( 2 1) which i s performed by expanding the enclosed volume of the vocal t r ac t .

Voiced stops in utterance initial position

The voiced stops a r e often produced without vocal fold vibrations in initial

position of an utterance. However, for thc subject used in this study the

vocal folds were always found to be in voicing position around 75 m s e c be-

fore the oral re lease , evcn if vocal fold vibration did not occur during the

occlusion. In Swedish the audibility of thc voicing for the voiced stops i s of

rLlinor importance. If thc vibrations happcn to stop during the occlusion it

will, however, have some acoustical conscquences a t the re lease of the stop.

There will then be a delay in the onset of voicing of about 15 m s e c and the

vibrations will s t a r t a t a slightly increased fundamental frequency a s corn-

pared with stops vrllich a r e voiced through. The acoustic opposition i s then

maintained by the length of the aspiratio11 of the voiceless stops. In Fig.

1-13-4 a schemat ic descr ipt ion of the variation in glottal a r e a , AG, for a

Fig. I-B-5. Recordings of the speech sound (a) and optical glottogram (b) for the sentence "saja sesen igen".

STL-QPSR 2-3/1972 18.

The measurements of pressure drop ac ross the glottis and voicing, which

a r e described ea r l i e r , indicate that a higher p ressu re drop a c r o s s the glottis

i s required for vocal fold vibrations to s t a r t than for vibrations to be main-

tained. The conditions for starting vibrations may therefore not be fulfilled

until the glottis has reached the voicing position. The voiced-voiceless allo-

phones of the [h) may also be explained in a s imilar way. The small glottal

opening for the [h] i s a s a rule not sufficient to stop vocal fold vibrations

whcn it i s preceded by a voiced sound. However, if the [h] i s preceded by

a voiceless segment, the conditions for starting vocal fold vibrations during

the abduction gesture may not be achieved and the rh] will becomc voiceless.

[h] and r 6 ] do not occur a s separate phonemes in languages probably

due to the fact that a n abduction sufficient to devoice an [h] in voiced con-

text should r e sult in an exce ssive loss of air. Language s like, for instance,

Japanese which has a voiceless rh] a r e tllcrefore found to be produced with

an o ra l constriction assimilated from thc context.

Timing of glottal abduction for voiceless stop consonants

For thc stop sounds the timing of the glottal abduction gesture and the

oral occlusion has been studied more extensively in one of the subjects, The

sound recording was made with the microphone placed 1 cm from the mouth

and the noise generated by the airflow gave quite accurate information about

the moments of ora l closure and release. l'le will here discuss glottal timing

for stops in five different positions: (1) in a s t ressed CV-syllable; (2) inl-

mediately after a s t ressed vowel; ( 3 ) after [s] ; (4) in s t ressed utterance

initial position; and (5) in utterance final position. No systenlatic differences

were found in the timing for [p], r t ] , and [1c] and they a r e therefore trcated

together.

For the stops the degree of s t r e s s will affect the length of the aspiration

which may disappear in unstressed position. Immediately af ter a s t ressed

vowel the aspiration i s a lso lost even if the syllable has a secondary s t ress .

The duration of the ora l occlusion i s in that position af te r a short vowel about

1. 5 t imes and af ter a long vowel 2 t h e s the length of the occlusion for the

voiced stop s in the same position. The r;lechanisms underlying this peculiari-

ty a r c not yet known. In other positions t l ~ c voiced and unvoiced stops have

about equal duration of the occlusion. In Fig. I -B-6 a schematic descrip-

tion i s given for thc glottal articulation for a voiceless intervocalic stop in

STL-QPSR 2-3/1972 19.

a s t ressed CV-syllable. The amplitude of the vocal fold vibrations A a r e g

shown separated f r o m the glottal a r e a in order to more clearly i l lustrate

the glottal articulation represented by thc curve A The peak amplitude A G '

of the glottis a r e a A cannot be measured accurately on the fiber scope film.

The values given a r e only approximations made f rom measurements on the

fi lm together with knowledge about the normal size of the laryngeal s t ructures .

The vibration amplitude of the glottal a r e a hzrs been estimated by coin- i i

paring the relations between A and A on the optical glottogram. A linear i

G g I

relation between ligkt pick-up and glottal a r e a has been assumed, -vhich

seems to be a ra ther good approximation. In a s t ressed syllable in an cm- 2

phasized word thc peak a r e a of the glottal abduction i s about 0.5 cm . The 2

vibration amplitude of the glottal a r e a seems then to be around 0. 15 c m . The values given in Fig. I-B-6 a r e max. and min. values f rom 15 ut terances

made by the same subject. The mean value for the duration of thc occlusion

was 95 msec. F o r low pitch the constriction of the larynx obscures the view

of the glottis and an estimation of the glottal a r e a i s more difficult to perform.

The variation in the baseline and in the vibration amplitude, which can be ob-

served in the optical glottogram of Figs. I -B-5 and I-B-8, i s mainly caused

by the variation in the laryngeal aperturc .

F r o m Fig. I-B-6 i t can be seen that the glottal abduction initiates in the

preceding vowel and that slightly more than half the peak amplitude i s reached

a t the instance of o ra l closure. This secl-ns to be typical for a l l the six sub-

jects used in this study. This fact will cause a slight preaspiration of the

stop sounds and it can sometimes be obscrvcd in the oscil logram recordings

that the voicing seems to stop slightly before the ora l closure. However, if

the vibrations of the vocal folds a r e studied on the optical oscillogram it can

be seen that the vibrations do not stop until one or two cycles after the closure

of the vocal t r ac t i s performed.

The preaspiration of voicele s s stops i s more pronounced in the position

immediately af ter a s t r e s sed vowel which is i l lustrated in Fig, I-B-7. The

glottal abduction ge s ture is in that position timed slightly ea r l i e r than in the

s t ressed syllable, and a delay of up to 2 0 mscc can be measured on thc oscil-

logram f rom the cessation of voicing to thc instance of ora l closure. Even in

this position the vocal folds do not stop to vibrate until the ora l closure i s

performed. The ear ly timing of the glottal abduction gesture and the length-

ening of the o ra l occlusion resul t in a loss of post aspiration of the stop.

A G A A

6

A A

Voicing A 1

posit iond- V V

c ! l / Y > Amplitude of speech sound

*i

A *2

A2 A, w >

Time

Mean glottal area

I oral occlusion

11 aspiration

Peak area of vocal fold vibrations. ~ = - = 0 . ~ - 0 * 2 ~ ~ 2

T ime

Fig . I - B - 6 . Desc r ip t ion of the g lo t ta l a r t i cu la t ion f o r a voice- l e s s in te rvoca l i c s top in a s t r e s s e d CV-syl lable .

Amplitude of speech sound

1 v - I L 1

1 I *

area

U Voicing lag

Peak a r e a of vocal fold vibrations

___l_j Time

Fig. I -B-7. Description of the glottal art iculation for a voiceless con- '

sonant in the position immediately af ter a s t r e s sed vowel.

STL-QPSR 2-3/1972 20.

After a short vowel the duration of the occlusion i s longer than af ter a long

vowel but the timing pattern i s s imilar to that in Fig. I-B-7.

The amplitude of the abduction ge s turc i s about the same af ter a s t ressed

vowel a s before. Accordingly, the degree of glottal abduction i s not a function

of the amount of aspiration. However, the degree of glottal opening a t the i i 1

ora l re lease cor re la tes well with the duration of the aspiration. This has been

suggested to be the mechanism controlling aspiration(24) and our findings a r e ,

in agreement with this hypothesis.

The initiation of the glottal abduction gesture in the preceding vowel seems I

to have some influence on both pitch and duration of the vowel which may ex- (25) plain some intrinsic variation in the speech signal .

The glottal abduction gesture i s not completely reduced in unstressed posi-

tion. Only in c lus te rs after [ s ] there may be no abduction gesture associated

with the stop. It seems to be n universal fcature that stops af ter [ s ] a r c unas-

pirated. The mechanism behind this i s not fully understood although a t leas t

one explanation i s suggested in the i i to r l tc rc(26) . Fig. I-B-8 shows an op-

t ical glottogram of the word "spilcen" uttercd in a f rame sentence.

Voiceless stops in utterance initial position -

Fig. I-B-9 shows the glottal articulation for a voiceless stop in utterance

initial position. If the glottal closure is anticipated ear ly , a glottal stop i s

used in the same \-Jay a s has been described for the voiced stops.

If there i s a latc anticipation of glottal c losure, the abduction gesture

will be superimposed on the closure gesture which i s shown by curve I1 in

Fig. I-B-9. F r o m a functional point of view the glottis could a s well be timed

so a s to exhibit a cer tain degree of opening a t the ora l re lease omitting the

abduction gesture. This articulation should give the same acoustic result .

However, it seems a s if in the present case the motor system favors an in-

variance in the motor program rather than simplicity it1 the movements.

The abduction geoture for the voiceless consonants has not been observed

to be completely reduced even in unstre ssed position a s i t may be for Eng- ( 2 7 ) l ish speakers .

,,::;; *,..<f,; .' ------ , ..i,T,f ;$ii;$qf'i/2;;f;j# -~$!j:i~;:js;j<~:',?;!i:$;,~!!.,w .. , . . . . , ,..:., I . . : ' I , , .

Fig. I-B-8. Recordings of the speech signal (a) and optical glottography (b) of the sentence "saja spik igen".

Fig. I-B-9. Description of the glottal articulation for a voiceless stop in utterance initial position.

A d

Voicln8

I Early anticipation of glottal closure. ( voicing position)

I1 Late anticipation of glottal closure. vciicing poiition)

\

A

= 0.5-0.9 AG

Mean glottal area posi t ionT / + *

Glottal stop T i me

+# Occlusion

A g A

c i

Aspiration

v Peak area of vocal fold vikration >

u I I T i m e 100 ms

STL-QPSR 2 -3/1972 21.

Voiceless stops in utterance final position

If the voiceless stop i s put in utterancc final position the abduction gesture

for devoicing the consonant will be s imilar to the terminating devoicing ges-

ture described ear l ie r . However, two peaks a r e most often found in the op-

t ical glottogram, a s i s shown in Fig. I-B-10. The f i r s t i s the peak associated

with the abduction gesture and the second i s , according to our interpretation

of the data, the terminating devoicing gesture. The terminating gesture in

this context does not seem to be motivated by acoustic constraints. Thus we

here have another exarnple of the preference for invariance over simplicity

a t an articulatory level.

The pitch-lower ing mechanism

While the mechanism for upward pitch excursion in speech has bccn studied

quite extensively on English subjects only little attention has been paid to the

pitch lowering mechanism used in tone languages and in languages with word

intonation.

It i s well known that in order to produce low pitch the vocal folds have to

be thick and lax. i ln inhibition of the crico-thyroid muscles alone is not suf -

ficient to shorten the vocal folds and a n t a ~ o n i s t s have to be brought into play.

Thc hypothesis has been put forward that the ary-epiglottic sphincters a r c

active for lowering the pitch and that they work in antagonism to the cr ico- (28) thyroid muscles .

Activity in these muscles causes laryngeal constriction. This i s a na r -

rowing of the larynx tube by a movement a t the arytenoids towards the tubercle

of the epiglottis by a rotation of the thyroid carti lage about i ts joint on the low-

e r poster ior pa r t of the cricoid cartilage. Our observations indicate that this

i s the normal pitch lowering mechanism. In Figs . I-B- I1 and I-B- 12 sequences

of f r ames from thc words ''hiven" and "litcn'' resp. uttered in isolation a r e

shown. The intonation curves together with the synchronizing signals a r e

shown a t the bottom of the figures. The pronounced pitch drop towards the

end of the utterance is a character is t ic of thc Eskilstuna dialect of this subject.

In these examples it can be seen that the larynx i s constricted towards the

end of the sentence. According to our observation this lowering of the pitch

is actively controlled although the opposite sometimes has been stated for Eng-

l ish speakers(29). Notice a l so that the larynx seems to be closer to the f iber- I scope and thus in a lligller position for the extreme low pitch. This i s 2t

v C I 1 ) Amplitude of speech sound

*a A

Voicing position,, > Mean glottal area

a Time P e a k a r e a of vocal fold vibra t ions

End of u t t e rance

F ig . I - R - 1 0 . Descr ip t ion of the glottal ar t icula t ion fo r a voiceless s top i n u t t e rance f inal position.

1 I I 1 I I I 1 0 0.1 0.5 1.0 sec.

t o I I

H z 3 0 0 n 0 n n 0 0 0 0 0 n 0 0 n 0 I

5 10 15 20

200 - t i: t a - n

- \

100 - - - - - -

I I I

0 0.1 0.5 1.0 sec.

F i g . 1-8-12.

FUWDANENTAL ERQUENCY

F i g . 1-8-13.

SYNC. SIGNAL

INTENSITY

s t j a 88:

FUNDAMENTAL FREQUENCY

F i g . 1-8-14.

STL-QPSR 2-3/1972

gesture. In Fig. I -B- I3 it can be observed that for the glottal stop the

l a r y n x i s a l so constricted but in addition there i s activity in the vocalis

muscles which can be inferred f rom the fact that the pitch is not lowered

by the constriction of the larynx. In addition the larynx appears to be in

a lower position for the glottal stop than in tllc end of the sentence. If this

i s a feature of the glottal stop i s not knovrn. In Fig. I -B- 14 the ~ e n t e n c e

[ seja AB igenl i s uttered by the same subject. As often used in this type

of sentences marking of the morpheme boundaries i s used(34). The ges-

ture used for morpheme boundary marking i s generally re fer red to a s

"glottal stop". However, according to the smooth pitch transit ion and the

similarity to the articulation towards the end of the utterance we would

r a the r , in this case, identify the performed gesture with the norinal pitch

lowering mechanism. Other subjects, on the other hand, seem to use in-

creased act ivi ty in the vocalis muscles in a s imilar situation, which i s

normal for a glottal stop.

F r o m EMG-experiments it i s known thzt a glottal stop i s performed

with high activity in the vocalis muscles and with inhibition of the cr ico-

thyroid muscles. According to our observations it seems unlikely that the

constriction of the larynx, that i s found fc r glottal stop, i s achieved only

by this mechanism. Instead there seem to bc additional activit ies in other

sphincter muscles such a s the ary-epiglottic muscle s. These muscles

seem to be active a l so for low-pitch ~honat ion . However, EMG-data f rom

these muscles a r e not available and further experiments have to be p e r -

formed to tes t this hypothesis;'

References: -----

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STL-QPSR 2-3/1972 24. cont. r e f . (2) I

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d F a a h o r g - f h d e r s e n , K. , Yanagihara, N. , and von Leden, H. : "Vocal pitch and intensity regulation. A comparat ive study of e l ec t r i c a l activity in the cr icothyroid musc le and the a i r f low r a t e ", Arch . Otolaryng. 85 - (1967), pp. 448-454.

STL-QPSR 2-3/1972 25.

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Hiroto, I . , Hirano, M . , Toyozumi, T . , and Shin, T . : "Elect romyo- graphic invc stigation of the in t r ins ic laryngeal musc l e s re la ted to speech sounds", Ann. Otol. - 76 (1967), pp. 861-872. I Hirano, M. , Icoike, Y . , and von Ledcn, H. : ] 'The sternohyoid musc le ! during phonat ion. Elect romyographic studie s", Acta oto -1aryng. (1967), pp. 500-507.

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Hirano, M. , Vcnnard, W. , and Ohala, J . : l fRegulation of r e g i s t e r , pi tch, and intensity of voice: An elect romyographic investigation of in t r ins ic

I

laryngeal musc les" , Fo l iz Phon. - 22 (1970), pp. 1-20.

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Sawashima, M. , Gay, T. , and H a r r i s , K. S. : "Laryngeal musc le activity dur ing vocal pitch and intensity changes", Haskins Labora tor ies SR - I 9/20 I

(1969), pp. 211-220.

Siixadn, Z. 2nd Hirone, H. : "The function of the laryngeal musc l e s in I r e spe ct to the word accent distinction'", Annual Bulletin, R e s ea r ch Insti- tute of Logopedics and Phonia t r i cs , Univ. of Tokyo No. 5(197 I ) , pp. 41 -49.

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Gbrding, E. : "Word tone and la rynx ~ x u s c l c s f ' , Working P a p e r s , Univ. of Lund, No. 3 (1970), pp.20-46.

Gzrding, E. , Fu j imura , 0. , and Hi rose , H. : "Laryngeal control of Swedish word tones", Annual Bulletin, R e s e a r c h Institute of Logopedics and Phonia t r i cs , Univ. of Tokyo No. 4 (1970), pp. 45-54.

Ohman, S . , Miirtcnsson, B . , Leandcrsson , R . , and P e r s s o n , A. : "Crico-thyroid and vocalis musc le activity in the production of Swedish tonal accents : A pit ot study", STL-QPSR 2-3/1967, pp. 55-57.

STL-QPSR 2-3/1972 26.

Basmaj ian, J . V. and Stecko, G. : "A new bipolar e lect rode fo r c l ec t ro - myography", J. ilppl. Physiol . - 17 (1962), p. 849.

Sawashima, h1. and Hi rose , H. : "New laryngoscopic technique by u s e of f ibe r optics", J . i l cous t . S a c . ~ l m . - 43 (1968), pp. 168-169.

Sawashima, M . , Hi rosc , H. , Kiri tnni , S . , and Fuj in lura , 0. : " f~ r t i cu l a to ry movements of thc larynx", P r o c . of the 6th International Congr,ess on f ~ c o u s t i c s , Tokyo 196G, pp. B-1 - B-4.

Sawashima, h4. , Abramson, A. S. , Cooper , F. S. , and L i s k c r , L. : "Observing laryngeal adjustments during running speech by u s e of a f iberopt ics sys tem", Phonetics - 22 (1970), pp. 193 -201.

Sawashima, Ll. and Ushijitna, T. : "Use of the f iberscopc in spccch r e sea rch" , Annual Bulletin, Re s ea r ch Institute of Logopedic s and Phonia t r i cs , Univ. of Tokyo No. 5 (197 I ) , pp. 25-34.

Lislcer, L . , Sawashima, M. , R b r a ~ l s o n , A .S . , and Cooper, F .S . : "Cinegraphic observat ions of the larynx dur ing voiced and voiccless stops", Haskins Labora tor ies , SR-21/22 (1970), pp. 201-212.

Sawashima, h4. : "Glottal adjustnlents for Engl ish obst ruents ; ' , Haskins Labora tor ies SR-21/22 (1970), pp. 1C7-200.

Lindqvist, J. : "Laryngeal mechanisms in speech1 ' , STL-QPSR 2 -3/1969, pp. 26-31. I

Lindqvist, see ref . (2)d.

Lindqvist , see ref . (8)g.

Fa i rbanks , G. : "A theory of the specch mechanism a s a s e rvo - systenl", I

J . of Speech and Hearing D i so rde r s - 19 (1954), pp. 133-139. i I

Abbs, J . and Netzell, R. : "The inferent ia l r o l e of the G;?imina loop in I speech production: A new application of an old technique , papcr p r e s -

ented a t the 1970 Conv. of the Am. Speech and FIearing !~ssociation, New York.

McNeilage, P. : "ldotor control of s e r i a l o rder ing of speech1' , Psycho- logical Rcview - 77, No. 3 (1970), PP. 1C2-196. 1 Snlith, T. S. and Lee , C. Y. : "Per iphera l feedback mechanisms in speech lxoduction models ? ", paper p r c scnted a t the V1Itl1 International Congress of Pllonctic Sciences , liiontreal 197 1, to be publ. by Mcuton & Co., The Hague ( fo r thco~ning) .

see Lindqvist, ref . (8)g.

~ e s s & n , E . : VBra folkmsl, F r i t z e s ( ~ u n d 1966).

Sivcr tsen, E. : Coclmey Phonology, Oslo Studies in Engl ish No. 6 , - - Publ. of thc Br i t i sh Institute in thc Univ. of Oslo (Bergen 1960).

see Lindqvist, ref . ( 8 ) g .

Blecker t , L. : "Om bctoning och diftongering i EskilstunalnSlctl ' , ~orskn ingskommit t6 in i Uppsala f o r modern svenska (FUMS), Rcpor t No. 15(1970).

I Halle, M. and Stevens, K. N. : "On the mechanism of glottal vibration fo r vowels and consonants", MIT, QPR No. 85 (1967), pp. 257-271.

Halle, M. and Stcvcns, K. N. : "A note on laryngeal features" , MIT, QPR No. 101 (1971), pp. 198-213.

I

STL-QPSR 2-3/1972 I

27.

(18) Hi rose , H. and Gay, T . : "The activity of the laryngeal m u s c l c s in voicing control: An ele c t romyographic study1', Ha skins Lnborator ie s SR-28 (1971), pp. 115-142.

(19) Klatt , I?. H. : "Articulatory activity and xirflow dur ing the production of fricative consonants1' , MIT, QPR No. 84 (1967), pp. 257-260.

(20)s Sawashima e t a l , s ee ref . (8)c.

b L i ske r e t a l , sce ref . (8)c. I

I 1

(2 1) Rothenberg, M. : ' Thc Brea th-S t rcamDynamics of S imple Released- P los ive Product ion, Ka rge r (Base1 1968).

(22) Lindqvist , sec ref . (8)g.

(23)a Sone s son, B. : "Dic funktionelle Anatomic d e s Cricoarytancoidgclenke s t ' , Z. f. Anatomie und Entwicklungsgc schichte - 12 1 ( 1959), pp. 292 -303.

b Kaplan, H. M. : ~ l n a t o m y and Physiology of Speech (New York 1960), p. 154.

c von Leden, H. and Moore, P. : "Tlle rncchanism of the cr ico-arytenoid joint", Arch. Otolaryng. (Chic) - 73 (1961), pp. 541 -550.

(24) Kim, C - W . : ~ ' J L theory of aspirat ion", Phonct ica - 2 1(1970), pp. 107 -1 16.

(25)a Moore, B. : "Intrinsic var ia t ions in the speech signal1', Phonetica - 23 (1971), pp. 65-93.

b Chen, M. : "Vowel length variat ion a s a function of the voicing of the consonant environment", POLA, Univ. of California Berkeley No. 9 (1969).

(26) See Kim, rcf . (24) fo r a hypothetical explanation.

(27) Sawashimn, c t a l . , ref . (8)c.

( 2 8 ) Lindqvist, rcf . (8)g and Lindqvist , ref . (2)d.

(29)a L ieberman, P. : -- Intonation, - Percep t ion , - - - - - - -. -- and - Language, MIT P r e s s (Cambridge, Mass. 1967);

b H a r r i s , K.S. , Gay, T . , L ieberman, I?. , and Sholes, G.N.: "The function of n ~ u s c l e s in control of s t r c s s and intonationf' , Maskins Labo- r a t o r i e s , ~ ~ - 1 9 / 2 0 (1969), pp. 127-138.

(30) irhman, S. : "J170rd and sentence intonation: A quantitative nlodclt l , S.rL-QPSR 2-3/1967, pp. 20-5'1.

( 3 1)a Hadding, Koch, K. : Acoustico-Phonetic Studies in Intonation of Southern Swedish, t h e s i s (Lund 1961).

b Segerback, B. : L a Rbaiisation d 'unc opposition de tonsmes dans de s dissyl labe s chuchoxs - ( ~ u n d 1966).

(32) See Lindqvist , ref . ( 8 ) ~ .

(33) hleyer -Eppler , W. : "Realization of prosodic feature s in whispered speech", J . fA~cous t . Soc.Am. - 29 (1957), pp. 104- 106.

(31) Gsrding, E . : "Laryngeal boundary signals", Working Pnpc r s , Univ. of Lund No. 4 (1971), pp. 23-47.