the effects of hearing loss on binaural function€¦ · spatial release in speech-on-speech...
TRANSCRIPT
![Page 2: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/2.jpg)
•Outline
Whatarethemajoradvantagesoftwoears?
Howdotheleftandrightsignalsdiffer?Howdoweusethisinformationphysiologically?
Howwellcanweexploitourtwoearsforimportanttasks?LocalizationofsoundsourcesAttendingtosourceofinterestincomplexsituations
Effectsofhearingimpairmentinbinauralprocessing...Interauralparametersensitivityandspeechwithspeechmaskers.(astudybyNathanSpencerinmylab).
Whatlimitsperformancewithimpairments/aids/implants?
![Page 3: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/3.jpg)
Whatarethemajoradvantagesoftwoears?
Redundancy
Localizationofsources
Identifyingroomcharacteristics(size,shape,wallreflectivity,and???)
TheCocktailPartyEffect…Renoir's“LuncheonoftheBoatingParty”
![Page 4: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/4.jpg)
![Page 5: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/5.jpg)
•LocalizationCues:
•ITD:fareardelayed•ILD:farearattenuated•SpectralShapes
Differentsignalsatthetwoears
![Page 6: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/6.jpg)
InterauralTimeDelay(ITD)•versusazimuthθ
•DurlachandColburn, 1978
![Page 7: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/7.jpg)
•InterauralLevelDifference(ILD)•ILDversusazimuthfortwofrequencies•Measurementsandspherecalculations
![Page 8: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/8.jpg)
SpectralShapeInformationasalocalizationcue
![Page 9: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/9.jpg)
Outer Ear (beige), Middle Ear (pink), Inner Ear (Blue, cochlea)
![Page 10: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/10.jpg)
•
lConsiderstimuluscodingandbinauralprocessinginphysiologicalstructures.
lQuickreviewofperipheralphysiology
lAuditoryNerveResponsesandTimingInformation
lSuperiorOlivaryNucleicompareleftandrightresponseswithsensitivitytoITDorILD
PhysiologicalMechanisms
![Page 11: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/11.jpg)
Middle Ear bones
Cochlear spiral
Vestibular and Auditory Nerves
Semicircular Canals
Stapedius muscle attaches to third bone (stapes) and contracts to decrease transmission
May respond in anticipation of loud sounds
![Page 12: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/12.jpg)
RecordingsfromthreeindividualauditorynervefiberswithNOACOUSTICSTIMULUS
![Page 13: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/13.jpg)
•Primary Auditory Nerve Patterns (Kiang, 1965)
•Note the stochastic nature of the response
![Page 14: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/14.jpg)
Rate-intensityfunctionforauditorynervefiber
![Page 15: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/15.jpg)
AuditoryNerveTuningCurves:Levelrequiredfordetectableresponse
![Page 16: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/16.jpg)
![Page 17: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/17.jpg)
Histogramsofresponsestotonesatvariouslevels
Notethathistogramsherecovertwoperiodsofthetonalstimulus
Synchronizationtotonecycles
![Page 18: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/18.jpg)
•JeffressmodelofITDprocessing
•Howdoprocessthistiminginformationtocomparerightandlefttimings
•JeffresspostulatedCoincidenceDetectorNetworkin1948.
•Internaldelaysthataredifferentforeachcellinanarray
•Fixedtimedelayoninputpatternswouldexcitecompensatingdelaycellmoststrongly
![Page 19: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/19.jpg)
•Coincidence Network of Jeffress (1948)
![Page 20: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/20.jpg)
ITD-sensitive neuron in MSO
![Page 21: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/21.jpg)
![Page 22: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/22.jpg)
![Page 23: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/23.jpg)
•MechanismsofITDProcessing
•CodingoftimestructuretoneuralpatternlPrimary auditory nerve coding
•Maintenance/sharpening of temporal structurelSharpening in cochlear nucleus (Bushy Cells of CN)
•Sensitivity to delays of left and right inputslSingle neuron processing in MSO
•Preservation to higher neural levelslMaintenance of “spatial code” for ITD
![Page 24: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/24.jpg)
From Stern and Trahiotis, 1997
Binaural Display: (f,τ)-plane
Narrowband Cross-correlation function for each f
Internal delay limiting function
Resulting distribution of activityITD from ridge
![Page 25: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/25.jpg)
![Page 26: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/26.jpg)
•Interaurallevel(ILD)representation
•LSOneurons(ILDandonset-ITDsensitive)
•Excitatoryinputfromipsilateralside
•Inhibitoryinputfromcontralateralside
•ArrayofILDprocessorsversusfrequency
![Page 27: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/27.jpg)
•DiraniehandColburn,1994•(MODEL)
•LSONeuronandILDsensitivity
![Page 28: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/28.jpg)
•ILD,farrayofLSOneurons
•LSOneuronsareeachILDsensitive
•LSOneuronsaretunedinfrequency(likeauditorynervefibersandMSOcells)
•ProvideinformationaboutILDforeachfrequencyband
•Maybeparticularlyimportantinreverberantenvironments(Hartmann,1999)
![Page 29: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/29.jpg)
InterauralDifference(ITDorILD)ResolutionforHumanSubjects
•Howsmallatimedelaybetweentheearsisreliablydetectablebyahumanlistener?
•CalledaJust-NoticeableDifferenceinITDorILD
•Bestlistenerscandobetterthan10µs −− on the order of ten millionths of a second!
•Best listeners for ILD do about 0.5 decibels
![Page 30: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/30.jpg)
InterauralDifferenceSensitivityversusfrequency
![Page 31: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/31.jpg)
EnvelopecarriesITDatHF
• Temporalsynchronizationtotimingfallsoffathighfrequencies…
• MinimalsensitivitytofinestructureITDaboveabout1500Hzinhumans
• Buthighfrequenciescarryinterauraltiminginformationinsynchronizationtotheenvelopes.Thisisafactorinbinauralperformancebutitiscomplicated.
![Page 32: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/32.jpg)
Envelopeonnoisebandprovidestimingcues
Neuralsynchronizationtotheenvelope(blackcurvewithfrequenciesrelatedtobandwidth)
Nosynchronizationtothefinestructure(i.e.,tothecarrier)athighfrequencies
![Page 33: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/33.jpg)
Howdowehandlethecocktailparty?
• Combinedstimulimixedtogetherineachfrequencyband
• Wewanttousetheinternaldistributionsoverfrequencyandinterauralparameters…maybebasedoninterauraltimeandlevelormayinvolveprocessed,position-basedinformation
• Thesedisplayschangeovertimeasdifferentstimulifromdifferentdirectionsdominate.
• Thisisacomplexchallenge!
![Page 34: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/34.jpg)
Sortingitallout
• Theinformationhastobethere.• Weneedtoignoredistractingsources
– Evidencethatmusicianscandothisbetter– Practicemakesusbetterinanycase– Calledinformationalmaskingversus“energetic”
• Weneedtoexploittheinterauraldifferencesaswellasthedynamictemporalvariations
• Weneedtouseourknowledgeofthesignals
![Page 35: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/35.jpg)
InterauralSensitivitywithHearingLoss(NathanSpencerExperiments)
• Primaryinterestwaseffectsofhearingimpairmentsonbinauralprocessing.
• Measuredinteraural discriminationaswellasspatialreleaseinspeech-on-speechmasking.
• Hypothesizedthatinteraural discriminationability[just-noticeabledifferences(JNDs)ininteraural time,level,andcorrelation]wouldco-varywithspatialseparationbenefits.
![Page 36: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/36.jpg)
NathanSpencerSubjects
• Tenyoungnormal-hearingsubjects,aged20-29
• Tenyounghearing-impairedsubjects.• HI1-HI8,HI10,HI11;aged19-38
• Oneolderhearing-impairedsubject• HI9aged70
![Page 37: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/37.jpg)
/36/6 2 3 5 9 /36/6 2 3 5 9 /36/6 2 3 5 923121191715131
21191715131
21191715131
211917151311
Gsf r vf odz!)l I { * Gsf r vf odz!)l I { * Gsf r vf odz!)l I { *
IM)
eC*
IM)
eC*
IM)
eC*
IM)
eC*
HearingImpairedaudiograms
HI1 HI2 HI3
HI6HI5HI4
HI7 HI8 HI9
HI10 HI11
25yearsold,male
18,f 19,f
19,m 24,m
37,m 22,f
38,f
29,f29,m
70,m
AudiogramssymmetricinallcasesexceptforinHI10,anauthorinthiswork.
![Page 38: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/38.jpg)
Interauraldifferencesensitivitytasks• Stimuli1/3octave,narrow-bandnoises,centeredateitherlowfrequency(500Hz)orhighfrequency(2kHzor4kHz).
• Measuredjust-noticeabledifferences(JNDs),relativetodioticreference(waveformssameinbothears)
§ Interauraltimedifference(ITD)discrimination§ Interauralleveldifference(ILD)discrimination§ Interauralcorrelationdifference(ICC)discrimination
![Page 39: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/39.jpg)
Measuringinterauraldifferencesensitivitythresholds
• Acquiredadaptivetracksto(Levitt,1971)70.7%correct
• Keptmeasuringperformanceinalltasks,overmultipledays
• Calculatedthresholdsanderrorbarsbasedonlasttwelveadaptivetracks
![Page 40: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/40.jpg)
ITDsensitivitymeasurements
• Ininterval2orinterval3,waveformwasdelayedinoneear,relativetoother…creatinganoff-centerimageinonlyoneinterval
• Presentedfourintervals
• Subjectaskedtoidentifywhichinterval(2or3)wasdifferent
• Providedwithfeedback
![Page 41: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/41.jpg)
NormalHearingITDthresholds
2 3 4 5 6 7 8 9 : 2122
Opsn bm!I f bsjoh
Mph!
21!)JM
E*!)e
C* 2
1
.2Mpx
!Gsf
rvfo
dz
2
1
.2
Ijh
i!Gsf
rvfo
dz
JME
!)eC
*
!
!
23456789:211/2
2
21
OI !5!l I {2 3 4 5 6 7 8 9 : 21 1/2
2
21
2 3 4 5 6 7 8 9 : 21Mpx
!Gsf
rvfo
dz Opsn bm!I f bsjoh
Mph!
21!)JU
E*!)µ
t*
µ
2
3
4
!
!
JUE
!)µt*
21
211
2111
OI !611!I {OI !611!I { !N f bo
Increasingaveragehearingloss(<10 dBdifferencecumulative)
2 3 4 5 6 7 8 9 : 21
Mph!
21!)J
UE*!)µ t
*
Opsn bm!I f bsjohMp
x!G
sfrv
fodz
Ijh
i!Gs
frvf
odz
2
3
4
21
211
2111
2 3 4 5 6 7 8 9 : 21 µ
JUE
!)µ t
*2
3
4
21
211
2111
(Basedonenvelopetiming)
![Page 42: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/42.jpg)
2 3 4 5 6 7 8 9 : 21
2
3
4Mp
x!G
sfrv
fodz
Opsn bm!I f bsjoh I f bsjoh!Jn qbjsf e
Ijh
i!Gs
frvf
odz
2
3
4
Mph!
21!)J
UE*!)µ t
*
2 3 4 5 6 7 8 9 : 2122
21
211
2111
2 3 4 5 6 7 8 9 : 2122 µ
JUE
!)µ t
*
!
!
21
211
2111
I J!5l I {I J!3l I {
2 3 4 5 6 7 8 9 : 21 µ
HearingImpairedITDthresholds(right)
Increasingaveragehearingloss
WilcoxonMedianTest…
p>0.05
![Page 43: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/43.jpg)
ILDThresholds(Notelogscale)
2 3 4 5 6 7 8 9 : 2122.2
1
2
Opsn bm!I f bsjoh I f bsjoh!Jn qbjsf e
Mph!
21!)J
ME*!)
eC*
2
1
.2
Mpx
!Gsf
rvfo
dzI
jhi!
Gsfr
vfod
z 234567 21222323456789:21221/2
2
21
2 3 4 5 6 7 8 9 : 2122 µ!
!
JME
!)eC
*
1/2
2
21
2 3 4 5 6 7 8 9 : 21 µ!
!
WilcoxonMedianTest…
p>0.05
WilcoxonMedianTest…
p>0.05
![Page 44: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/44.jpg)
HearinglossasafunctionofinterauraldifferencesensitivitythresholdsforHI
21 2111
61
211I M!bu!611!I { !)eC* Bwf sbhf !I M!)eC*
JUE!Mpx !Gsf r /!)µt *
23 4
5
6
7
8
9:2122
eC!I
M
21 211 2111
23 45 6789
: 2122
• Nocorrelationsfoundforeitherofthesubjectgroups,foranyinterauraldifferencesensitivitytask
• LackofcorrelationfoundforHIgroupinITDat500Hz
![Page 45: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/45.jpg)
2
4
21Opsn bm!I f bsjoh I f bsjoh!Jn qbjsf e
mph21!JUE!)µt *
mph21!JME!)eC*
JUE!Mpx !Gsf r vf odz!)µt *
JME
!)eC
* !Mpx
!Gsf
r/!I
jhi!
Gsf
r/
JUE!I jhi !Gsf r vf odz!)µt *
234
5
6
7 89
:
21 23
4
5
6
7
89
:
2122
21 211 2111
23
4
5
6
7:
21
21 211 2111
2
4
21
234
5
6
7 89
ILDthresholdasafunctionofITDthreshold
r²=.59
r²=.73
r²=.79
r²=.88
![Page 46: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/46.jpg)
21 211
21
211
2111Opsn bm.I f bsjoh I f bsjoh.Jn qbjsf e
mph21!JUE!)µt *
mph21!JME!)eC*
JUE!Mpx !Gsf r vf odz!)µt *
234
56
789
:
21
21 211
2
3
57
:
21
2 4
2
4
21
mph21!JUE!)µt *
mph21!JME!)eC*
JME!Mpx !Gsf r vf odz!)eC*
JUE
!Ijh
i!G/
!)µt*
JME
!Ijh
i!G/
!)eC
*
23
4
5
6
789
:21
2 4
2
3
4
5
6
7
:
21
.41 .31.36
.31
.26
.21
.6
1
JDD!Mpx !Gsf r vf odz!)eC*
2
34
56
78
9
:
21
JDD
!Ijh
i!G/
!)eC
*
.41 .31 .21
2
3
4
56 7
9
:
21
r²=.84 r²=.25
r²=.73
r²=.68
r²=.88
r²=.94
IDJNDmeasurementsweregenerallycorrelatedbetweenlowandhighfrequencies,consideredacrosssubjects
![Page 47: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/47.jpg)
2
4
21Opsn bm.I f bsjoh I f bsjoh.Jn qbjsf e
mph21!JUE!)µt *
mph21!JME!)eC*
!JME
!Mpx
!)eC
*JM
E!I
jhi!)e
C*
!JDD
!Mpx
!)eC
*!JD
D!I
jhi!)e
C*
JUE!Mpx !Gsf r vf odz!)µt *
23
4
5
6
7 89
:
21 23
4
5
6
7
89
:
2122
23
4
5
6
7
:
212
4
21
23
4
5
6
7 89
21 211.41
.31
.21
234
56
789
:
21
21 211 2111
23
4
5 67
8
9:2122
2 4 21.36
.31
.26
.21
.6
1
2
34
5 6
789
:
21
JME!I jhi !Gsf r vf odz!)µt *
2 4 21
2
3
4
567
:
21
![Page 48: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/48.jpg)
Previousstudies:individualdifferencesininter-auraldifferencesensitivity,notinmonaurallevelsensitivity
• Four,highlytrainedNormal-Hearinglistenersat500Hz(Koehnke etal.1986)…
MONAURALdiscrimination
INTERAURALdiscrimination
![Page 49: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/49.jpg)
InterauralDiscriminationConclusions
• Largeinter-subjectvariability
• Interauraldifferencesensitivitythresholdsdidnotcorrelatewithhearingloss
• ITDandILDthresholdshighlycorrelatedamongbothNHandHIsubjectgroups
• Consistentwithmyseeing“remarkablesubjects”whowereexcellentinbinauraltaskswithseverehearingloss
![Page 50: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/50.jpg)
The famous psychologist George A.Miller once wrote:
"It is said that the best place to hide aleaf is in the forest, and presumably thebest place to hide a voice is among othervoices" (p. 118).
Miller,G.A.(1947) "Themaskingofspeech,"Psychol.Bulletin,44,105-129
Understanding speech in competition with other speechcan be challenging.
NowturntotheCocktailPartyProblem
![Page 51: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/51.jpg)
![Page 52: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/52.jpg)
•E.ColinCherry’s1953summary:
•“Howdowerecognizewhatonepersonissayingwhenothersarespeakingatthesametime(the‘cocktailpartyproblem')?”
•Factors:lVoices from different directionslLip-reading, gestures, and the likelDifferent speaking voices, pitches, speeds, …lAccents differinglTransition-probabilities (subject matter, voice dynamics, syntax, …)
![Page 53: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/53.jpg)
ObtainingSRTs
• UsedproceduresdevelopedbyCarr(2010)(nowCarrLevy)• Adaptivealgorithmusedtodeterminethetarget/masker(T/M)
ratio(dB)for50%correct§ Maskerlevelsfixed
§ NormalhearingEachmaskersetto~45dBaboveSRTinquiet(65dBSPL)
§ HearingimpairedEachmaskerset~25dBaboveSRTinquietinHI,whenpossible
§ Targetlevelvaried
• ForHI11,discomfortthresholdslimitedmaskerlevel,sotargetcouldbelimitedbyaudibility(lessthan10dBabovequietthreshold,Duquesnoy,1983)
![Page 54: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/54.jpg)
Colocated task
6m
10mDifficultcase,ingeneral…
• Alltalkersinthesameposition• Noseparation-relatedcues
~Infront
Sources~1.5mawayfromhead
![Page 55: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/55.jpg)
Symmetricmaskerscondition
6m
10mModeratelydifficult…
• Interauraldifferences• Nolong-termbetterear
~Infront
~60⁰~60⁰
~1.5m
![Page 56: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/56.jpg)
Anti-symmetricmaskerscondition
Expectedtobeeasierthancolocated…
• Long-termbetterear,contralateraltoearwithdominantmasker
• Interaural timedifferences• Interauralleveldifferences
~60⁰ ~Infront
Sources~1.5mfromhead
Measuredperformancebothright-earbetterandleft-earbetter
![Page 57: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/57.jpg)
Colocated task
6m
10mDifficultcase,ingeneral…
• Alltalkersinthesameposition• Noseparation-relatedcues
~Infront
Sources~1.5mawayfromhead
![Page 58: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/58.jpg)
Colocated SRTs
Limitedbyaudibilityp>0.05
2 3 4 5 6 7 8 9 : 21
Opsn bm!I f bsjoh I f bsjoh!Jn qbjsf eT
SU!U
0N!)e
C*
1
.21
.31 µ!
!
2 3 4 5 6 7 8 9 : 2122 µ!
!
WilcoxonMedianTest…
![Page 59: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/59.jpg)
Anti-symmetriccondition
Expectedtobeeasierthancolocated…
• Long-termbetterear,contralateraltoearwithdominantmasker
• Interaural timedifferences• Interauralleveldifferences
~60⁰ ~Infront
Sources~1.5mfromhead
Measuredperformancebothright-earbetterandleft-earbetter
![Page 60: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/60.jpg)
Anti-symmetricSRTs
2 3 4 5 6 7 8 9 : 21
Opsn bm!I f bsjoh I f bsjoh!Jn qbjsf e
1
.21
.31
TS
U!U0
N!)e
C*
µ!
!
Dpmpdbuf e!N pobvsbm
2 3 4 5 6 7 8 9 : 2122 µ!
!
Dpmpdbuf eMf gu!Cf uuf s!N pobvsbmSjhi u!Cf uuf s!N pobvsbm
†p<0.05
• “Spatialreleasefrommasking”
• Individualdifferencesareevident
WilcoxonMedianTest…
†
![Page 61: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/61.jpg)
• Monauralbenefit = Colocated – separatedmonaural
Determiningbenefitsofspatialseparation
• Binauralbenefit=Totalbenefit– monauralbenefit
• Totalbenefit=colocated - spatiallyseparated
2 3 4 5 6 7 8 9 : 21.31
.26
.21
.6
1
6
Opsn bm!I f bsjoh I f bsjoh!Jn qbjsf e
TS
U!U0
N!)e
C*
µ!
!
Dpmpdbuf e!Npobvsbm
2 3 4 5 6 7 8 9 : 2122 µ!
!
Dpmpdbuf eMf gu!Cf uuf s!NpobvsbmSjhi u!Cf uuf s!Npobvsbm
Colocated
Monaural
Binaural
Separatedmonauralismeasuredatbetterear
![Page 62: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/62.jpg)
Anti-symmetricbenefitsofspatialseparation
Largemonauralbenefit
1
21
31OI !Cf of gju I J!Cf of gju
Cjo
bvsb
m!)eC
*
31
21
1
Upub
m)eC
*
µ µ
!
!
Bt zn !Mf gu!Cf uuf sBt zn !Sjhi u!Cf uuf s
1
21
31
Npo
bvsb
m!)eC
*
2 3 4 5 6 7 8 9 : 21 2 3 4 5 6 7 8 9 : 2122
WilcoxonMedianTest…†
†
†
†p<0.05
†p<0.05
†p<0.05
![Page 63: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/63.jpg)
Anti-symmetricbinauralbenefit
2 3 4 5 6 7 8 9 : 21
OI !Cf of gju I J!Cf of gju
Cjo
bvsb
m)eC
*
µ µ
21
6
1
.62 3 4 5 6 7 8 9 : 2122
Highinter-subjectvariabilityinbothgroupsWilcoxonMedianTest…
†p<0.05
†
![Page 64: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/64.jpg)
1
21
31Bouj.t zn n f usjd!Cf of gju
2
3
4 5 6 789
:21 2222
Upub
m)eC
*
1
21
31N
pobvsb
m)eC
*
23 4 5 6 7 8
9 :21 2222
1 31 51 71 91 211.6
1
6
21
Cjo
bvsb
m)eC
*
23
45 6
789
:21
2222
Nf bo!I M!)eC*
Anti-symmetricbinauralbenefitasafunctionofhearingloss
r2=.55
![Page 65: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/65.jpg)
ILD500ILD4k
ITD500ITD4k
r2 shownintableRedmeansp<0.05
BinauralBenefitr2 <0.2r2 =0.67
r2=0.51r2 =0.39
Anti-symmetricbinauralbenefitasafunctionofinterauraldifferencesensitivity
NH
BinauralBenefitr2 <.2r2 <.2
r2 <.2r2 N/A
BinauralBenefitN=8r2 =.53N=6r2= 0.64
N=8 0.54N=4 r2 N/A
HI1-8(<70dBHL)HI1-10
Correlationformost interauraldifferencesensitivitythresholds
Correlationfornointerauraldifferencesensitivitythresholds
Correlationforsomeinterauraldifferencesensitivitythresholds
![Page 66: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/66.jpg)
Symmetrictask
6m
10mModeratelydifficult…
• Interauraldifferences• Nolong-termbetterear
~Infront
~60⁰~60⁰
~1.5m
![Page 67: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/67.jpg)
Symmetricbinauralbenefit
Highinter-subjectvariabilityamongeachsubjectgroup
2 3 4 5 6 7 8 9 : 21
OI !Cf of gju I J!Cf of gju
µ µ
1
6
21
Cjo
bvsb
m)eC
*
2 3 4 5 6 7 8 9 : 2122
WilcoxonMedianTest…
†
†p<0.05
![Page 68: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/68.jpg)
Symmetricbinauralbenefit
• Binauralbenefitdidnotcorrelatewithhearinglossineithergroup
• Binauralbenefitdidnotcorrelatewithinterauraldifferencesensitivitythresholdsineithergroups
![Page 69: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/69.jpg)
DataConclusions
• Hearinglossakeyfactorinthebinauralbenefitfortheanti-symmetricconditionbutnotforthesymmetriccondition
• Inmostcases,hearing-impairedlistenersbenefitedfrombinaurallistening§ Binauralbenefitsmostlypositiveforanti-symmetric condition§ BinauralbenefitswerealwayspositiveforHIinthesymmetric condition
• Intheanti-symmetriccondition,binauralbenefitwascorrelatedwithsomeinterauraldifferencesensitivitythresholdsforbothnormal-hearingandsubsetofhearing-impairedlisteners
§ Inthesymmetriccondition,binauralbenefitnotcorrelatedwithinterauraldifferencesensitivitythresholds
![Page 70: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/70.jpg)
Timewindowprocessingfactor?
• Inthesymmetriccase,withspeechmaskers,listenersbenefitfromselectivelylisteninginoptimaldirection(and/ortothebetterear)differentlyindifferenttimeintervals
• Thisfactorisdistinctfrominterauralresolutionfactorsandfromattenuationfactors
![Page 71: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/71.jpg)
•Speech Spectrogram
lTime(about3.5seconds)
lFrequency (kHz)
![Page 72: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/72.jpg)
EffectofECwindowlengthonSRT(1xJitter)
31 61 311.31
.26
.21
.6
1
6
X joepx )n t *
Tzn n f usjd Bouj.t zn n
Qsf
ejdu
fe!T
SU)e
C*
31 61 311
Consistentbetter-ear
Inconsistentbetter-ear
![Page 73: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/73.jpg)
OverallConclusionsforthisstudy
• Binauralbenefitinanti-symmetricconditionforHIgroupdecreaseswithhearingloss
• Interauraldifferencesensitivityakeyfactorforbinauralbenefitforanti-symmetricspeechcondition§ Correlationswereobservedfornormalhearinggroupandfor
hearing-impairedsubgroupwithless-than-severeaveragehearingloss
§ Modelpredictionsshowlargeeffectofjitterstandarddeviation
• Interauraldifferencesensitivityandhearinglosseachunrelatedtobinauralbenefitforsymmetriccondition§ Neitherinterauraldifferencesensitivitynorhearinglosscorrelated
withbinauralbenefitinthesymmetriccondition§ Modelingresultsshowinfluenceofprocessingwindowduration§ Suggestindependentestimationofprocessingwindowlength
![Page 74: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/74.jpg)
Takehomemessage?
• Theprocessinginmultiplespeechinterferencesituationsisverycomplex– Dependsonlocations,natureofsources,positionsofmaskers,individualabilitytousethemultiplecues,andpossiblyontemporalwindowfactors.
• Neithertheaudiogramnorabilitiestodosimplediscriminationtasksarepredictorsofabilitiesincomplexenvironments
• Teststobedonewithhearingaidsincomplexenvironmentsseemimportanttodevelop.
![Page 75: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/75.jpg)
Ongoingworkonthistopic(withTheoGoverts atVUMC)
• Attempttocharacterizedifficultenvironments– Recording(binaurally)difficultenvironmentsasreportedbylistenerswithhearingimpairments
• Analysisofrecordingsandcomparisonswithsubjectiveimpressions
• Worktodevelopaspeech-in-complex-environmentstestthatcouldbeusedtoevaluatehearingaidsintheclinic.
![Page 76: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/76.jpg)
Physical Acoustics
L(t)
R(t)
Current Model of Sources and Environment
ITD,f array
ILD,f array
freq spectra
ITD,f array
ILD,f array
freq spectra
Compare
Actual to
Hypothesis
Update Mechanism
Peripheral Physiology
Listener’s Learned Transformations
Non-auditory inputs
Real Sources in the real Environment
Fast (Add/Delete/Move Source)
Slow (Pinna)
Internal Representations
ColburnandKulkarni(2005)
StableWorldModel
![Page 77: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/77.jpg)
Acknowledgements
• IRChearing-aidcompanyconsortium
• NationalInstitutesofHealthGrantsupport:– NIDCDR01DC00100
• ManyColleagues,especiallyGeraldKidd,TheoGoverts,SuzanneCarr Levy,NathanSpencer
![Page 78: The Effects of Hearing Loss on Binaural Function€¦ · spatial release in speech-on-speech masking. • Hypothesized that interaural discrimination ability [just-noticeable differences](https://reader035.vdocuments.us/reader035/viewer/2022081408/60607fc8f70cc84f1a7cc868/html5/thumbnails/78.jpg)
TheEnd!!