Child-LevelFactors&Acquisitionofthe/t/--/k/Contrast:ProductionAllisonJohnsona,Sara(Bernstein)Clineb,PatrickF.Reidya,MaryBeckmanc,BenjaminMunsonb,&JanEdwardsa
Background
! Whatdoweknowaboutspeechdevelopmentinchildrenwhoaretypicallydeveloping?(Smitetal.,1990;Macken&Barton,1980)
! Whatdoweknowaboutthe/t/--/k/placecontrastanditsdevelopmentinyoungchildren?(Stevens,2000;Hewlett,1987)
! Howisspeechcharacterizedinresearchandinpractice?(Munsonetal.,2010)
! Whatarethedownsidestotranscription?(Munsonetal.,2010;Gibbon,1999;Gibbon,1990)
! Howcanacousticanalysissupporttranscription?(Nicholsonetal.,2015;Hollidayetal.,2014;Forrestetal.,)
! Whyarefine-grainedmeasurementsclinicallyrelevant?(Tyler,Figurski,&Langsdale,1993)
Objectives
! Performspectralanalysisofstop-consonantreleaseburststodescribefine-grainedvariabilityin/t/and/k/productionsin2-3-yearoldchildren
! Useapsychoacousticallyrelevantmeasureoffrequency—PeakERB—asasummarymeasure,ratherthanaphysicalmeasureoffrequency(i.e.,Hz)
! DevelopaRobustnessofContrastmeasuretodescribechildren’sacquisitionofthe/t/--/k/contrast
RobustnessofContrast
! Objectivemeasurebasedonauditoryspectralanalysisofthestopreleaseburst
! %Tokenscorrectlypredictedbymixedeffectslogisticregressionmodel
Summary
! PeakERBdifferentiates[t]and[k]betterinbackvowelcontextsthaninfrontvowelcontexts
! AdultsshowarangeinRobustnessofContrastacrossallvowelcontexts(65%-100%)
! ChildrenshowagreaterrangeinRobustnessofContrast,evenwhenanalyzingproductionsthatweretranscribedascorrect(51%-100%)
! 80%oftheadultshadatleast90%oftheirtokenscorrectlypredictedacrossallvowelcontexts
! 29%ofthechildrenhadatleast90%oftheirtokenscorrectlypredictedinbackvowelcontextsonly
! Noneofthechild-levelvariablesweresignificantpredictorsofRobustnessofContrast
FutureDirections
! Exploreadditionalmeasurestohelpdifferentiate[t]—[k]infrontvowelcontexts
! Explorehowintermediateproductionswereclassified
! CompareRobustnessofContrastfor[t]—[k]productionstootherspeechcontrasts,suchas[s]—[ʃ]or[ɹ]—[w]
! LookatchangeinRobustnessofContrastovertime
! SeeifRobustnessofContrastin2½-3-year-oldchildrenpredictsanychild-levelvariablesoneyearlater
! SeehowRobustnessofContrastvariesacrossdifferentpopulations(e.g.,childrenwithcochlearimplants)
Coding! Praat1. Segmentwordboundariesand
coderesponsecontext
2. Mannertranscription(stop,other)3. Place[narrow]transcription
SpectralAnalysis:AnalyzableData:! Stopproductions! Transcribedas[t],[k],orintermediate! VOT>20ms! Unobscuredbybackgroundnoise
ToComputePeakERB:! Fromthe.WAVrecording,extract5msprecedingburstthrough
20msfollowingburstwitharectangularanalysiswindow! EstimatethespectrumofthewindowusingaMultitaper
spectrum(K=8,NW=4)! Passthespectrumthroughagammatonefilterbank(tobetter
representthehumanauditoryfilter)! Passthespectrumthroughahigh-passfilter(toreduce
contaminationofthesignalduetoambientbackgroundnoise)! Outputwillshowapsychoacous/cspectrumrela/ng
excita/oninagammatonefiltertoitscenterfrequencyalongtheERBscale
! ThefrequencywiththegreatestamplitudeisthePeakERB—oursummaryacous/cmeasure
ToCalculateRobustnessofContrast:! Mean-centerPeakERBtoimproveinterpretabilityofthe
model! Buildamixedeffectslogisticregressionmodeltopredict
TargetConsonant(either/t/or/k/)fromPeakERBvalues:TargetConsonant~PeakERB+VowelContext+PeakERB*VowelContext+
(1+PeakERB|ID)! Calculatethelog-oddsforeachproduction:whatisthe
likelihoodthattheproductionisa[t]or[k],givenitsPeakERBandthevowelcontext
! Calculatetheaccuracyofeachprediction! Calculatethe%ofeachchild’stokensthatwerecorrectly
predictedbythemodel
Acknowledgements
Supportedby:• NIDCDgrantR0102932toJanEdwards• NICHDP30HD03352granttotheWaismanCenter• T32TrainingGrantDC05359-10toSusanEllisWeismer
SpecialThanks:LearningtoTalklabmembersforhelpingcollect,code,andanalyzedata.
Learningtotalkpar/cipantsandtheirfamiliesformakingthisworkpossible.Visitlearningtotalk.orgformoreinforma/onaboutourlabandahandoutofthisposter.aUniversityofWisconsin-MadisonbUniversityofMinnesota-TwinCitiesCOhioStateUniversity
DataCollectionParticipants! n=111! Females=51,Males=60! LivingnearMadisonorMinneapolis! Monolingual,nativeEnglishspeakers! Normalhearing! LateTalkers(n=11)! African-AmericanEnglishspeakers(n=14)andMainstreamAmericanEnglishspeakers(n=97)
DataAnalysis:Coding
ASHAAnnualConvention,Nov.2015
VisitTasks! DemographicQuestionnaire(parenttask)! LanguageEnvironmentAnalysis(LENA™)! HearingScreening! ExpressiveVocabularyTest—2ndedition
(EVT-2;Williams,2007)! PeabodyPictureVocabularyTest—4thedition
(PPVT-4;Dunn&Dunn,2007)! Goldman-FristoeTestofArticulation—2ndedition
(GFTA-2;Goldman&Fristoe,2000)! MinimalPairDiscriminationTask! Real-WordRepetitionTask
Real-WordRepetitionTask:Stimuli! 34productionsof/t/-and/k/-initialwords! 17different,familiarwords! Presentedaloudfromacomputer! Pairedwithpictureonthescreen! 16/t/tokens,8inbackvowelcontexts! 18/k/tokens,8inbackvowelcontexts
4.TaglocationsofreleaseburstandVOT
TranscriptionCategoriesTarget/t/! [t]:clear,correct[t]! [t:$k]:intermediate,closertocorrect! [$k:t]:intermediate,closertoincorrect! [$k]:clearsubstitutionof[k]for/t/Target/k/! [k]:clear,correct[k]! [k:$t]:intermediate,closertocorrect! [$t:k]:intermediate,closertoincorrect! [$t]:clearsubstitutionof[t]for/k/
MaternalEduca5on nLow 14Middle 26High 70
ChildCharacteris5c n Mean(SD) Range
Age(months) 111 32.6(3.5) 28-39
EVT-2standardscoreNorm:100(15)
109 116(17) 81-160
PPVT-4standardscoreNorm:100(15)
109 113(18) 79-153
AdultNorms:! TodeterminehowwellPeakERBdifferentiates[t]and[k]
productions,wetestedthemodelson16adultspeakers
Results:! [t]and[k]werebetterdifferentiatedinbackvowelcontexts
comparedtofrontvowelcontextsforbothchildrenandadults! Children’sproductionswerehighlyvariable! ChildrenhadagreaterrangeinRobustnessofContrastmeasures
comparedtoadults,evenforproductionstranscribedascorrect
Effectsofbetween-categorydistanceandwithin-categorydispersionondiscriminability.Topgraphshowspoordiscriminabilityduetolowbetween-categorydistance(a)andhighwithin-categorydispersion(b).Bodomgraphshowsgooddiscriminabilityduetohighbetween-categorydistance(a)andlowwithin-categorydispersion(b).
