SpeechrateSpeechrateislowerinCDS(Beta=-70,SE=9,p<0.001).Noeffectoftime.(Beta=1,SE=0.2,p<0.001)

CDS is not what you think - Hypoarticulation in Danish Child Directed SpeechChristinaDideriksen &RiccardoFusaroliAarhusUniversity

Introduction:ResearchoverthepastdecadeshasfoundevidenceforspecificacousticfeaturesthatseemtobeconsistentinCDSacrossdifferentlanguages(Fernald etal.1989,Kuhl etal.1997):• ahighpitchandahighpitchvariation• alowerspeechrate and• anincreasedvowelspace.However,DanishisunderstudiedwithregardstoCDSandwiththethevastnumberofspokenvowelsinDanish(appr.60,comparedtoca.20inUSEnglish,Basbøll 2005)andthedelayinlanguagecomprehensioninDanishchildren(Bleses 2008)wewantedtoinvestigatethisparticularaspectoflanguageacquisition.

Projectdetails:Wewantedtoemphasizetheimportanceofworkingwithecologicallyvaliddata.Thereforewecollecteddatafrom:

• 23Danishmothersandtheirchildren(between12-24months,M=17.73,SD=4.46)

• 1hourofspontaneouslyoccurringCDS• 15minutesofsemi-structuredmother-adultconversations.• Alldataiscollectedinthehomesoftheparticipatingfamilies.• Mothersfilledoutaquestionnaireaboutparentingattitudesafterthe

recordings

Procedure:• Motherswereinstructedtoplaywiththeirchildastheywouldnormally

do.• Afterwardsthemotherwouldhaveaninformalconversationwithan

adultinterviewer.• Motherswerenotinformedabouttheentirescopeofthestudybefore

aftertherecordingsession.

Materials:Orthographictranscriptionandtimecoding of10mother-childdyadsandthecorrespondingmother-adultdyadThisyielded:

• 3782utterancesfromthemotherintheCDS-condition• 1065utterancesfromthemotherintheADS-condition

Parentingattitudequestionnaires:• Negativeattitudetowards‘babytalk’• Thebeliefthatitisimportanttotalk‘clearlyandlively’toachildis

correlatedwithanexpandedvowelspaceandasmallerdifferencebetweenCDSandADS(Beta:-0.06489,SE=0.02576,t=2.52,p=0.041)

Vowelspace:• DoesasmallervowelspaceinCDSactuallyimpedelanguage

acquisitioninDanishorcouldithelpit?• Isthereasimilarpatterninothervowelrichlanguages?

Clustering• Themodeldefined12differentvowelclusters• Dispersionofvowelsisimportant.Anexpandedvowelspacecanbe

asignalofabigdispersionofvowels(Martinetal.2015).

PitchMedianpitchwaslowerinADS(Beta=-70,SE=9,p<0.001).Noeffectoftime.InterquartilerangewaslowerinADS(Beta=-26,SE=5.6,p=0.001).Noeffectoftime.

Vowelspace• CDShasadecreasedvowelspaceinCDS(Beta=0.1,SE=0.04,p=0.046(Bayesfactor2.2))

References:Basbøll,H.2005. ThephonologyofDanish.Oxford:OxfordUniversityPress.Bleses,D.etal.2008.EarlyvocabularydevelopmentinDanishandotherlanguages:aCDI-basedcomparison.JournalofChildLanguage, 35,619-650DeJong,N.H.&Wempe,T.2009.Praat scripttodetectsyllablenucleiandmeasurespeechrateautomatically.Behaviorresearchmethods,41,2,385- 390.Drugman,T.&Alwan,A.2011.JointRobustVoicingDetectionandPitchEstimationBasedonResidualHarmonics.PaperpresentedattheInterspeechFernald,A.etal.1989.Across-languagestudyofprosodicmodificationsinmothers’andfathers’speechtopreverbalinfants.Journalofchildlanguage,16,3,477-501Kuhl,P.etal.1997.Cross-languageanalysisofphoneticunitsinlanguageaddressedtoinfants.InScience,277, 684-686.Martin,A.etal.2015.Mothersspeaklessclearlytoinfantsthattoadults:Acomprehensivetestofthehyperarticulationhypothesis.PsychologicalScience,26,3.341-347.Sandoval,S.etal.2013.Automaticassessmentofvowelspacearea,inJournaloftheAcousticalSocietyofAmerica,134,5.477-483.

ThisprojectissupportedbyanInteractingMindsCenterseedfundingandthePuzzleofDanish,FKK-collectivegrant

Methodsandanalysis• Weusedlinearmixedeffectsmodels(lme4inR,Bates

etal.2014).• Individualvariationwasaccountedforbyincluding

participantIDasrandominterceptandregisterasrandomslope.

• Allacousticalelementswereautomaticallyextracted:• Fundamentalfrequency(summationof

theresidualharmonicsandfilteringforoutliers,Drugman &Alwan 2011)

• Speechrate(vowelonsetestimation,deJong&Wempe 2009)

• Vowelspace(Sandovaletal.2013)

• WeusedanautomatizedclusteranalysistoidentifyDanishvowelclusters.

• VowelspacewascalculatedfromF1andF2invoicedspeechsegmentsanddefinedastheareasurroundedbyclustercentroids.