Lay listener classification and evaluation of typical and ... · Final version accepted for publication in Language and Speech June 6, 2017. Lay listener classification and evaluation

FinalversionacceptedforpublicationinLanguageandSpeechJune6,2017.

Laylistenerclassificationandevaluationoftypicalandatypical

children’sspeech

MelissaA.Redford1,VsevolodKapatsinski1,JolynnCornell-Fabiano2

1DepartmentofLinguistics,UniversityofOregon

2CésarE.ChávezElementarySchool,EugeneSchoolDistrict4J

Runninghead:Classificationandevaluationofchildspeech

Keywords:Autism,likeability,intelligibility,prosody,acoustics.

Acknowledgments.ThisresearchwasfundedbyAwardNumberR01HD061458(PI:

Redford)fromtheEuniceKennedyShriverNationalInstituteofChildHealth&Human

Development(NICHD),andmadepossible,inpart,bythesupportoftheEugeneSchool

District4Jandafellowshiptothe1stauthorfromtheEuropeanInstitutesforAdvanced

Study(EURIAS),co-fundedbytheEuropeanCommission(Marie-Sklodowska-CurieActions

COFUNDProgrammeFP7).Thecontentissolelytheresponsibilityoftheauthorsanddoes

notnecessarilyreflecttheviewsofNICHD,theEugeneSchoolDistrict4J,EURIASor

COFUND.WearegratefultoAubrianneCarson,WookKyungChoe,andPaulOlejarczukfor

significanthelpwithdatacollectionandprocessing.

Classification and evaluation of child speech

1

ABSTRACT

Verbalchildrenwithautismspectrumdisorder(ASD)oftenalsohaveatypicalspeech.In

thecontextofthemanychallengesassociatedwithASD,dospeechsoundpattern

differencesreallymatter?Thecurrentstudyaddressedthisquestion.Structured

spontaneousspeechwaselicitedfrom34children:17withASD,whosecliniciansreported

unusualspeechprosody;and17typically-developing,age-matchedcontrols.Multiword

utteranceswereexcerptedfromeachchild’sspeechsampleandpresentedtoyoungadult

listeners,whohadnoclinicaltrainingorexperience.InExperiment1,listenersclassified

bandpassfilteredandunalteredexcerptsas“typical”or“disordered”.ChildrenwithASD

wereonlydistinguishedfromtypicalchildrenbasedonunalteredspeech,buttheanalyses

indicateduniquecontributionsfromspeechsoundpatterns.InExperiment2,listeners

providedlikeabilityratingsonthefilteredandunalteredexcerpts.Again,laylistenersonly

distinguishedchildrenwithASDfromtheirtypicallydevelopingpeersbasedonunaltered

speech,withtypicalchildrenratedasmorelikeablethanchildrenwithASD.InExperiment

3,listenersevaluatedtheunalteredspeechalongseveralperceptualdimensions.High

overlapbetweenthedimensionsofarticulation,clearness,andfluencywascapturedbyan

emergentdimension:intelligibility.Thisdimensionpredictedlisteners’likeabilityratings

nearlyaswellasitpredictedtheirjudgmentsofdisorder.Overall,theresultsshowthatlay

listenerscandistinguishatypicalfromtypicalchildrenoutsidethesocial-interactional

contextbasedsolelyonspeech,andthattheyattendtospeechintelligibilitytodothis.Poor

intelligibilityalsocontributestolisteners’negativesocialevaluationofchildren,andso

meritsassessmentandremediation.


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INTRODUCTION

TempleGrandin,diagnosedwithautismasachild,characterizedherearlyspeechin

thefollowingway:"Myvoicewasflatwithlittleinflectionandnorhythm.Thatalone

stampedmeasdifferent(Grandin&Scariano,1986:21).”Especiallyinchildhood,any

differencethatdeviatesfrompeer-definednormscanjeopardizeachild’saccesstopeer

friendshipsandsocialsupport.Forexample,inthedomainofspeechandlanguage,Rice

andcolleagueshaveshownthatchildrenwithspecificlanguageimpairmentandthosewho

learnEnglishasasecondlanguagehavelessaccesstopositivesocialinteractionsinUS

schoolsthantypicallydeveloping,nativeEnglish-speakingchildren(Rice,Sell,&Hadley,

1991;Gertner,Rice,&Hadley,1994).Atypicalspeechpatternsmayfunctionlikelanguage

disorderorincompletesecondlanguageacquisitionbycreatingbarrierstosocial

interactionforchildrenwithASD.Butunlikelanguagedisorderorincompletesecond

languageacquisition,theproblemmayhavelesstodowithcommunicationperseand

everythingtodowiththeconveyanceofdifference;specifically,adifferencethatresultsin

anegativesocialevaluation.ThispossibilitywasnotedevenbyAsperger(1944,as

translatedbyFrith,1991:70),whoconcludedhisdescriptionofatypicalspeechinchildren

withASDbysayingthat“thelanguagefeelsunnatural,oftenlikeacaricature,which

provokesridiculeinthenaïvelistener.”Thegoalofthepresentresearchwastotestthe

hypothesizedlinkbetweenatypicalspeechpatternsandanegativesocialevaluationof

childrenwithASD.Asecondarygoalwastoidentifythepatternsthatlaylistenersattendto

whenclassifyingchildren’sspeechastypicalornotandwhenevaluatingchildren’s

likeabilityasafunctionoftheirspeech.


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Background

Afairlysubstantialbodyofscientificworkconfirmsthatindividualswithautism

whospeakdoindeedproduceatypicalspeechsoundpatterns,andespeciallyatypical

speechprosody.Forexample,Shribergandcolleagues(Shriberg,Paul,McSweeny,Klin,

Cohen,&Volkmar,2001)usedtheversatileandcomprehensivebutunstandardized

Prosody-VoiceScreeningProfile(PVSP;Shriberg,Kwiatkowski,&Rasmussen,1990)in

theirstudyofspontaneousspeechin30individualswithASD:trainedlistenersevaluated

speechacrossavarietyofpredeterminedprosodicandvoicecategories,including

loudness,pitch,voicequality,resonancequality,phrasing,rate,andstress.Themost

consistentvoicedeficitwasinresonancequality:aninappropriatenasalqualitywasmore

oftenidentifiedinspeechproducedbyindividualswithASDthanbythecontrols.Themost

consistentprosodicdeficitwasstress;acategorythatincludedexcessive/equalstress,

prolongationandblockingtypedisfluencies,aswellasincorrectproductionoflexicalstress

patternsandaccentualpatternsatthelevelofthephrase(labeled“contrastivestress”).The

authorsreportthattheperceiveddifferencesbetweenindividualswithASDandcontrol

speakerswasduetoagreaternumberofperceiveddisfluenciesand“misplacedword

stress.”(p.1107).Insofarasanumberofotherperceptualstudiessimilarlyreportautism-

relateddeficitsintheproductionoflexicalstressandphrasalaccenting(e.g.,Baltaxe&

Guthrie,1987;McCaleb&Prizant,1985;Paul,Augustyn,Klin,&Volkmar,2005;Grossman,

Bemis,Plesa-Skwerer,&Tager-Flusberg,2010),itislikelythatdeficitsin“stress”

productionisadefiningfeatureofatypicalprosodyinASD.

Incontrasttoperceptualstudies,acousticstudiesonautisticspeechhavefocusedon

globalpatternsrelevanttocharacterizingtheprosodicdifferencesinindividualswithASD.

Forexample,Diehletal.(2009)extractedaverageF0(theacousticcorrelateofpitch)and


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itsstandarddeviation(=pitchvariability)overlargetemporalwindows(250+

milliseconds)innarrativespeechproducedbyatotalof38childrenandadolescentswith

ASDand38typicalcontrols.Theyfoundthatpitchvariabilitywasgenerallyhigherin

speechproducedbychildrenwithASDthanintypicallydevelopingchildren.Otherstudies

reportsimilarresults(Sharda,Subhardra,Sahay,…&Singh,2010;Bonneh,Levanon,Dean-

Pardon,Lossos,&Adini2011;Depape,Chen,Hall,&Trainor,2012;Nadig&Shaw,2012),

whichcouldbeconsistentwiththeabove-mentionedfindingofimpairedphrasalaccenting

inautisticspeechifpitchvariabilitycapturessomethingaboutaccentualpatterning.

Inadditiontodeficitsinlexicalstressproductionandphrasalaccenting,thereis

someevidencethatindividualswithASDproducespeechatslowerratesthantypical

controls(forareviewseeShriberg,Paul,Black,&vanSanten,2011).Forexample,Diehl

andPaul(2011)usedthesameglobalF0measuresasDiehletal.(2009)onutterances

obtainedfrom24childrenwithASDand22typicallydevelopingchildrenindifferent

subtestsoftheformallystructuredbutunstandardizedProfilingElementsofProsodyin

Speech-Communicationtest(Peppé&McCann,2003),butfoundnodifferencebetweenthe

groups.TheyalsotookmeasuresofF0rangeaswellasutterance-levelmeasuresof

acousticdurationandintensity.Onlydurationdifferencesweresignificant:childrenwith

ASDproducedlongerutterancesonaveragethanthetypicalcontrols.

Studiesthatuseperceptualevaluationormeasureglobalacousticstoidentify

prosodicdeficits/differencesassumeanexpandeddefinitionofprosodyrelativetothat

whichisassumedincarefullinguisticphoneticstudies.Butwhereasthelinguist’sinterest

isintherealizationofabstractmetricalandintonationalstructuresandthealignment

betweenthem,theclinician’sinterestisinidentifyingthosepatternsthatcouldadversely

affectanindividual’sabilitytocommunicatewith—inordertobeacceptedby—peers.The


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searchforprosodicdeficitsisthusexpandedtoincludeanysuprasegmentalpatternin

autisticspeechthatmightreliablysignaldifferenceordisorder.

Yet,evenwithitswidepurview,existingresearchonthedifferencesbetween

autisticandneurotypicalspeechreturnsfewconsistentfindings.Considerforexamplethe

contradictoryresultsonthestatusofatypicalpitchvariabilityinindividualswithASD:

Diehlandcolleagues(2009)findsignificantdifferencesbetweenchildrenwithandwithout

ASDinonetask,butDiehlandPaul(2011)findnosuchdifferencesinanothertask.Such

inconsistentresultsmaybeduetotheabsenceofdeficitsinasignificantproportionof

high-functioningindividualswithASD.Althoughsystematicdataonthedistributionof

atypicalprosodyinautismdonotyetexist,ithasbeensuggestedthatprosodicdeficitsmay

onlybeevidentinthespeechofhalfofallindividualswithASD(e.g.,Paul,Shribergetal.,

2005).

Despitecontradictoryfindingsandthepossibilitythatprosodicdisorderoccursin

onlyhalfofallhigh-functioningindividualswithASD,thetopicofprosodic

difference/deficitsinautismhasreceivedincreasingattentioninrecentyears.Whereas

McCannandPeppé(2003)foundthatbetween1980and2002only16studiesonprosody

inautism,ascholar.google.frsearchinearly2017on“prosodyautismprosodicASD”

returned1,010results.Thetop100results,whichincludedofarticles,conference

proceedingsandbookchapters,indicatedatleast57newstudies(i.e.,thosepublishedin

peer-reviewedjournals)thatwerefocusedonsomeaspectofprosodyorprosodic

processinginthespeechofindividualswithASD.Thiskindofattentionissurprisinggiven

thatautismis,afterall,characterizedprimarilybydeficitsinsocialcommunicationand

interactionaswellasbyrestrictedandrepetitivepatternsofbehaviorthataredisabling

(AmericanPsychiatricAssociation,2013).ThediagnosticcriteriasetforthintheDiagnostic


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andStatisticalManualofMentalDisorders(DSM-5)donotevenmentionatypicalspeech

soundpatterns,letaloneprosody.Theydohoweverreferencebehaviorssuchas“failureto

initiateorrespondtosocialinteractions”and“abnormalitiesineyecontactandbody

language...toatotallackoffacialexpressions”aswellasstereotypedorrepetitivemotor

movements…orspeech”(e.g.,echolaliaoridiosyncraticphrases).Giventhedisabling

natureofthecriterialbehaviorsinautism,whicharesocialorperseverativeinnature

ratherthanprosodic,isthereagoodreasontofocusevermoreresearchontheunusual

speechpatternsofindividualswithASD?Thisquestionmotivatedthecurrentstudy.

TheCurrentStudy

Thepracticedclinicianapparentlyhasnotroubleidentifyingindividualswith

autismbasedonatypicalspeechsoundpatternswhenthesearepresent(Klin,Sparrow,

Marans,Carter,&Volkmar,2000).Cliniciansintrainingcanalsoreliablydistinguish

speakerswithandwithoutautismbasedonshortconversationalspeechsamplesthatare

measurablydifferentwithrespecttopitchvariability(Nadig&Shaw,2012).Theseabilities

areperhapsnotsurprisinggiventhat,aslanguagespeakers,weareattunedtosound

patternsinspeechthatindexsocialinformation.Thissensitivityallowslistenerstoadeptly

categorizespeechbyethnolect(Lass,Almerino,Jordan,&Walsh,1980;Purnell,Idsardi,&

Baugh,1999),dialect(Clopper&Pisoni,2004;Clopper&Bradlow,2009),genderidentity

(Lassetal.,1980;Munson,2007),andsexualorientation(Munson,McDonald,DeBoe,&

White,2005;Munson,2007).Moreover,listenersdonotthemselvesneedtobeexpertin

thesocialcategoriesofinteresttoeffectivelyclassifyspeechbasedonsoundpattern

differences(Purnelletal.,1999;Clopper&Bradlow,2009).Forexample,Clopperand

Bradlow(2009)usedafreeclassificationtasktoshowthatnon-nativespeakerswereable

toclusterAmericanEnglishspeechsamplesbydialect,albeitlessaccuratelythannative


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speakersofAmericanEnglish.Otherstudiesstronglysuggestthattheperceptionofsocial

informationinspeechhassocialconsequences(vanBezooijen,1995;Purnelletal.,1999).

Forexample,Purnellandcolleaguesfoundthatlandlordsdiscriminatedagainsttenants

basedsolelyonspeechpatternsthatindexedanAfricanAmericanorChicanoidentity.

Ourautomaticidentificationofsocialinformationinspeechcoupledwith

impressionisticdescriptionsofatypicalspeechsoundpatternsinautismastooloud,shrill,

sing-songy,mechanicalandsoon(see,e.g.,Asperger,1944inFrith,1991;Klinetal.,2000)

suggestthatautisticspeechmaybenoticeabletoandsociallyevaluatedbylistenerswho

havenoknownpriorexperiencewithautism.Butthequestionremainsastohowimpactful

thesespeechdifferencesreallyare.Morespecifically,isitthespeechpersethatidentifiesa

personwithautismas“other”orisitperhapsthesuiteofunusualcommunicativeand

repetitivebehaviorstypicalofautismthatengendertheperceptionofotherness?Also,if

othernesscanbediscernedbasedsolelyonspeechpatterns,wouldsuchanidentification

resultinaninherentlynegativesocialevaluation?Tobegintoanswerthesequestions,the

currentstudytestedtheeasewithwhichlaylistenerscandistinguishchildrenwithASD

fromtheirtypicallydevelopingpeersbasedsolelyonshortsnippetsoftheirprosodically

impairedspeech.Wealsoinvestigatedhowlistenersevaluatedthisspeechabsentasocial

orlinguisticcontext.

Acousticstudiesthatfindgroupdifferencesbetweenautisticandneurotypical

speechstronglysuggestthatspeech-specificdifferencesarethereandshouldbe

perceptibleeventolaylisteners.Yet,eventhissuggestionhasyettoberigorouslytested.

TheperceptualratingstudyconductedbyNadigandShaw(2012)providessomeevidence

infavoroftheperceptualsaliencyofdifference,buttheirlistenerswerespeech-language

pathologistsintrainingwhowerealsospecificallytaughttoattendtopitchchangesinthe


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speechsamplesfromchildrenwithandwithoutASD.Inaddition,thesamplesthatNadig

andShaw’slistenersratedwereexcerptedfromconversationswithnocontrolover

languagedifferences(wordchoice,appropriatenessofresponse,etc.)thatcouldinfluence

judgmentsoftypicality.Thecurrentstudyprovidesamorerigoroustestofthehypothesis

thattheatypicalspeechproducedbychildrenwithASDandunusualprosodyis

perceptuallydistinctfromtypicalchildren’sspeech(Experiment1).Aftershowingthatitis,

wegoontoinvestigatewhetherperceiveddifferenceresultsinanegativesocialevaluation

ofthespeaker(Experiment2).Wefollowupbyidentifyingtheperceptualdimensionsthat

listenersusebothtodistinguishatypicalfromtypicalspeechandtosociallyevaluatea

speaker(Experiment3).Themethodsweusecontrolasbestaspossibleforinfluencesof

social-interactionalcontextonlisteners’classificationandevaluationofspeech:weelicited

children’sspontaneousspeechinanarrativetask,ratherthaninaconversationalone,and

furtherdecontextualizedeventhisspeechbyextractingonlyafew,fluentlyproduced

utterancesfromeachnarrative.Thestimuliandjudgmenttaskswerealsodesignedtotest

thefundamentalsaliencyofprosodicdifferences,andtocontrolforpossibleeffectsof

languageonlisteners’evaluationofspeechpatterns.Finally,weusedlaylisteners,whohad

noknownaprioriexperiencewithASDandrelativelylittleexperienceonaveragewith

children,tomaximizethepossibilitythatlistenerjudgmentswerereflectiveofbroader

societalnormsratherthandependentonpersonalhistoriesandexperiences.Intheseways,

wesoughttoanswerourmotivatingquestionofwhethertheatypicalspeechsound

patternsoftenassociatedwithASDarethemselvesimportanttoaddressdirectlygiventhe

manyothersocially-disablingbehaviorsmorecentraltoautism.


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EXPERIMENT1

ThegoalofExperiment1wastotestlaylisteners’abilitytodistinguishchildren

withASDfromtheirtypicallydevelopingpeersbasedsolelyontheiratypicalspeech.The

hypothesisthatlistenerswouldbeabletodothisfollowsfromourautomaticidentification

ofsocialinformationinspeechandfromacousticstudiesthathavemeasuredandfound

differencesinspeechproducedbymanychildrenandadultswithASDcomparedtothose

withoutASD,particularlyintheprosodicdomain.Sincethesestudiesalsoshowthat

prosodicdeficitsdonotappearinallindividualswithASD,weobtainedspeechsamples

onlyfromchildrenwithASDwhowerealreadydeemedbytheirspeech–language

pathologisttohaveunusualspeechprosody.

Methods

Participants

Sixteencollege-agedadultsprovidedlayjudgmentsofdisorder.Theseadultswere

recruitedfromintroductorypsychologyandlinguisticsclasses,andreceivedcoursecredit

fortheirparticipation.AllreportednormalhearingandEnglishastheirnativelanguage.

Thelistenersevaluatedspeechobtainedfrom34children,whoalsohadnormalhearing

andEnglishastheirnativelanguage.Seventeenofthechildren(14boys)hadspecial

education(SPED)eligibilitiesforreceivingspeechandlanguageservicesintheschools

underautismspectrumdisorder(ASD).Theirmeanagewas9;0years(SD=18months).

Theother17children(13boys)weretypicallydeveloping.Theirmeanagewas8;9years

(SD=15months).

ChildrenwithASDwererecruitedforthestudythroughalocalnetworkofschool

speech–languagepathologists(SLPs)in2011.TheSLPswereaskedtoreferchildrenfrom

theircaseloadwhohad(1)aSPEDeligibilityunderASD,(2)normalcognition,and(3)


10

unusualprosody.InthestateofOregon,adeterminationofautismforSPEDeligibilityis

madebytheschooldistrictandinvolvesateamofeducationprofessionalsincludinga

schoolSLPandclinicalpsychologist.Thisteammakestheirdeterminationbasedon

observationofthechildinandoutoftheclassroom,andusesassessmentinstrumentsto

evaluatetargetbehaviors,cognition,speechandlanguage(seeOregonAdministrative

RulesforSpecialEducationathttp://www.ode.state.or.us/offices/slp/spedoars.pdf).The

AutismDiagnosticObservationSchedule(ADOS;Lord,Rutter,Pamela,Dilavore,&Risi,

2008)isnotused,norisamedicaldiagnosisofautismrequiredoracceptedasasubstitute

forafullevaluationbythedistrictteam.Regardingunusualprosody,wereliedonthe

schoolSLP’sinterpretationofwhatthismightmeaninkeepingwithboththegoalsofthe

studyandtheverybroaddefinitionofwhatconstitutesprosodyinresearchonautistic

speech.

Wecollecteddatafrom18childrenwhowerethuslyreferred,butonechild’sspeech

wasaccidentallynotrecorded.Symptomseverityfortheremaining17childrenwas

measuredbyaskingthereferringSLPtocompletetheChildhoodAutismRatingScale

(CARS2;Schopler,VanBourgodien,Wellman,&Love,2010).Parentalreportwasusedto

establishwhetherornotthechildhadexperiencedlanguagedelay.Receptivevocabulary

scoreswereobtainedusingthePeabodyPictureVocabularyTest(PPVT-4;Dunn&Dunn,

2007).Table1reportsthesex,age,ASDsymptomseverity,languagedelay,and

standardizedreceptivevocabularyscoresforeachchild.

InsertTable1abouthere.

Typicallydevelopingchildrenwerenotspecificallyrecruitedforthecurrentstudy.

Instead,thesechildrenrepresentedasubsetof100childrenwhohadparticipatedina


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longitudinalstudyonthetypicalacquisitionofprosodyinschool-agedchildren,whichwas

on-goingatthetimeofthecurrentstudy.Speechsampleswereselectedfrom17ofthe

childrenwhobestmatchedtheASDgroupinageandsexatthetimeofthepresentstudy.

Typicaldevelopmentwasassessedbasedonparentreportregardingthechild’shearing,

speech,language,andmedicalhistory.Themeanageinthisgroupwasnotsignificantly

differentfromthemeanageinthegroupofchildrenwithASD.Table2reportsthesex,age,

andstandardizedreceptivevocabularyscoresofthetypicallydevelopingchildren.


ElicitationProcedure

Structuredspontaneousspeechsampleswereobtainedusingastorytellingtask.An

experimenterpresentedchildrenwith4picturebooksthatdepicteddifferentadventures

ofafrogand/oraboyandadog(i.e.,thefrogstorybooksbyMercerMayer).Childrenwere

askedtochoosethepicturebookthats/hewouldmostliketonarrate.Typicallydeveloping

childrenfamiliarizedthemselveswiththeirbookofchoiceunderexperimenter

supervision,thentoldtheirstorytoaparentorcaregivertwotimes.Storyrepetitionwas

usedtocontrolfortheeffectsoflanguageplanningonthespeechproduced(seeRedford,

2013).Asourinterestisinspeechandnotincognitiveinfluencesonlanguageproduction,

thesamplesusedinthepresentstudywereextractedfromthechildren’ssecond

storytelling.

PilotworkindicatedthatchildrenwithASDresistedtellingthesamestorytwicetoa

parentorcaregiver.Theelicitationprotocolwasthereforeadaptedinthefollowingway.

Childrenchoseabooktonarrate,thendevelopedastoryinresponsetoquestionsand

promptsfromtheexperimenterwhilelookingthroughtheirbookofchoice.Thechild’s


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caregiverwastheninvitedbackintotheroom(ortheconversationiftheyhadnotleft),and

thechildwasinstructedto“telltheirstory”tothecaregiver.Thescaffoldingprocedure

servedthesamefunctionasafirststorytellinginourstudyontypicallydeveloping

children’sspeechacquisition:itallowedchildrentoplantheirstoryandpracticethe

languagetheywouldusetotellthestory.

Allchildren’sstoriesweredigitallyrecordedontoaMarantzPMD660(witha

samplingrateof44,100Hz)usingaShureULXS4standardwirelessreceiverandalavaliere

microphone,whichwasattachedtoabaseballhatorheadbandthatthespeakerwore.

ChildrenwithASDwouldsometimesrefusetowearthehatorheadband,inwhichcasethe

microphonewasplacedeitheronthechild’sclothingoronthetablebetweenthe

experimenterandchild.

SpeechSamples

Fourmultiwordutteranceswereextractedfromthemiddleofeachchild’sstoryto

avoidthestereotypedlanguageandprosodyassociatedwithstorybeginningsandendings.

Utteranceswereselectedonthebasisofprosodiccompletenessandlength:utterancesthat

wereroughly2secondslongwereselectedoverthosethatwereshorterormuchlonger.

Thegoalwastoselectphrasesthatwouldbestrepresentphrase-levelrhythmand

intonation(hencetherelativelylongminimumlength)whilecontrollingforsignificant

juncturesduetopausesandotherdisfluencies(hencetherelativelyshortmaximum

length).SamplesfromchildrenwithASDrangedinlengthfrom1.12to3.37seconds(M=

2.21)andfrom4to14syllables(M=8.08).Samplesfromtypicallydevelopingchildren

rangedinlengthfrom1.45to3.06seconds(M=2.17)andfrom5to14syllables(M=9.15).

Onceutteranceswereextracted,filteringwasusedtocreatestimuliforapure

prosodycondition.Theunalteredutteranceswereusedtocreatestimuliforthe


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correspondingfullspeechcondition.Thegoalofthemanipulationwastotesttheextentof

prosodicdifferenceinthespeechofASDversustypicallydevelopingchildren,keepingin

mindthatfilteringalwayssubstantiallydegradesthespeechsignal.

Twodifferentbandpassfilterswereused:onepreservedlowerfrequencies(250to

750Hz)andtheotherhigherfrequencies(500to1000Hz).Thebandpassfilterthat

preservedlowerfrequencieswasusedtocapturerhythmicinformationassociatedwiththe

alternationofsonorantandnonsonorantspeechintervals.Thebandpassfilterthat

preservedhigherfrequencieseliminatedtheremaininglowfrequencyenergyassociated

withthosesonorantconsonantsproducedwithsignificantoralocclusioninonsetposition.

Thegoalofthisfilterwasthereforetopreserveinformationaboutthespacingofvowel

onsets,whichhavebeenreferredtoastheperceptualcentersofrhythmicbeatsinspeech

(Port,2003).Notethatpitch(i.e.,F0)informationwaspreservedunderbothmanipulations

becauselistenerscalculatepitchfromthefrequencyspacingbetweenpreservedharmonics

(Moore,1994).Intheend,filtertypehadnosignificanteffectonlistenerjudgmentsandso

werecombinedintheanalysesreportedbelow,whichthereforeonlyrefertofilteredand

unalteredspeechsamples.

Filteredandunalteredutteranceswereamplitudenormalizedto75dBusingthe

scalefunctioninPraat(Boersma&Weenik,2009).Individualutterancesfromeachspeaker

werethenconcatenatedinrandomordertocreatestimulithatwereblockedbyspeaker.

Utteranceswereseparatedby300millisecondsofsilenceineachblock.Blockingwas

deemednecessarybecausepilotworkindicatedthatnaïvelistenersneedtohearmorethan

2secondsofspeechfromasingleindividualtomakeareliablejudgment.Theblocks

rangedindurationfrom7.27to12.51seconds(M=9.80)forchildrenwithASDandfrom

8.18to10.86seconds(M=9.51)fortypicallydevelopingchildren.


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ClassificationTask

Listenerswereaskedtomakejudgmentsof“typical”and“disordered”basedonthe

speechsamples.Listenersalsoindicatedtheirconfidenceineachjudgmentona5-point

ratingscale.Allresponseoptionsweredisplayedaslabeledbuttonsonacomputer

monitor.Thetwoalternativejudgments,“typical”and“disordered”,wereplacedinarow

abovetheconfidenceratingscale,whichalsoappearedasarow.Listenerswouldheara

stimulusblock,makeajudgment,ratetheirjudgment,thenpress“OK”tocontinueinthe

task.Stimulusblockswerepresentedinrandomorder.Listenersheardonelow-frequency

bandpassfilteredstimulusblockandonehigh-frequencybandpassfilteredstimulusblock

perspeaker,andsomadeatotalof68typicalityjudgments(34speakersx2repetitions)in

thefilteredspeechcondition.Listenersheardthesameunalteredstimulusblocktwice,and

soalsomadeatotalof68typicalityjudgmentsinthefullspeechcondition.

Listenerinstructionsincludedinformationaboutthespeakers,abouthowthe

speechstimuliwerecreated,andtheeffectofbandpassfilteringonspeech.Specifically,

listenersweretoldthatthespeechsampleshadbeenelicitedfromchildrenbetweenthe

agesof5and11yearsold,andthathalfofthechildrenwerereceivingspeech-language

servicesintheschool.Listenerswereassuredtheresearchobjectivewastohelptarget

speech-languagedeficitsinchildrenwithdisability,andsotheyshouldnotfeelinhibitedin

assigningajudgmentof“disordered”toanyspeechsampletheythoughtwasproducedbya

childwithdisability.Listenerswerealsotoldthattheutterancesthatmadeupeachsample

weretakenfromalargerstorytellingtask,andthatthestorycontextwasnotpreserved.

Finally,listenersweretoldthatsomeofthespeechtheywouldhearwasfilteredtoremove

asmuchlanguageinformationaspossible.Theywereinstructedtomakejudgmentsbased

onwhatremainedperceptibleinthefilteredspeech;namely,rhythmandintonation.The


15

experimenteralsomadesurethatlistenersunderstoodwhatspeechrhythmandintonation

were.Theseinstructionsweregiventoprovidelistenerswitheveryopportunityto

distinguishchildrenwithASDfromtheirtypicallydevelopingpeerswhenprosodyalone

waspreservedinthefilteredsignal.

Finally,inordertogaininsightintothebasisforjudgmentsof“typical”versus

“disordered,”weaskedlistenerstoprovidewrittenfeedbackregardingtheirperceptual

criteria.Specifically,listenerswereaskedto:“Pleasedescribethecharacteristicsinthe

speechsamplesthatledyoutodistinguishbetween“typical”and“disordered”speech

(please,especially,notewhatyouthinkmadethespeechsounddisordered).”Listeners

respondedtothisrequesttwice:firstaftercompletingjudgmentsinthefilteredspeech

condition,andthenagainaftercompletingjudgmentsintheunalteredspeechcondition.

ControlTasks

Twoadditionaltaskswereincludedintheexperiment;bothwereusedtocontrolfor

theeffectsoflanguage(e.g.,wordchoice,syntacticstructure,samplecoherence)on

“typical”and“disordered”judgments.Thecontroltaskforthefilteredspeechcondition

investigatedtheeffectivenessofthefilteratremovinglanguageinformation:listeners

indicatedroughlyhowmanywordstheythoughttheyunderstoodinthefilteredspeech

samplesona5pointscale:none,some,half,most,orall.These5responseoptionswere

presentedinarowofboxesonthemonitor.Confidenceratingswereagaincollectedon

eachjudgmentthatthelistenermade.Thecontrolfortheunalteredspeechcondition

directlyinvestigatedeffectsofwordchoice,syntacticstructure,andotherlanguage

featuresontypicalityjudgments.Thistaskrequiredlistenerstomake“typical”or

“disordered”judgmentsbasedonwrittenversionsoftheutterancesratherthanonaurally

presentedversions.Thewrittenversionsofaspeaker’sutterancesweredisplayedfor10


16

secondstoapproximatethedurationoftheaudiosamples.Listenersworeheadphones

whenmakingtext-basedjudgmentsjustasinallotherconditions,theythenclickedon

“typical”or“disordered”asintheotherclassificationtasks,andalsoindicatedtheirdegree

ofconfidenceintheirjudgment.

Theexperimentalandcontroltaskswerealwayscompletedinthefollowingorder:

filteredspeech,comprehension,text(i.e.,writtenstimuli),unalteredspeech.Thefixed

orderhadtodowiththefactthatfilteringonlyeffectivelyeliminatesaccesstolanguage

contentiflistenershavenoaprioriexpectationsaboutthiscontent.

Analyses

Thebinaryresponseswerecoded“0”for“typical”and“1”for“disordered”and

summedacrosslistenerstoobtainasinglescoreforeachsampleineachofthetaskswhere

thisresponsewaselicited.Judgmentscoresintheexperimentaltaskswerethenstrippedof

languageinfluenceinthefollowingway.Standardizedcomprehensionratingscoresfor

eachsamplewereusedtopredictthesummed“disordered”scoresinthefilteredspeech

condition(i.e.,acrossfiltertype)usinglinearregression.Similarly,summed“disordered”

scoresfromthetext-onlyjudgmenttaskwereusedtopredictthesummed“disordered”

scoresintheunalteredspeechcondition.Theresidualscoresfromtheseanalyseswere

saved,andthetwoscoresperspeakeraveragedtoobtainthedependentvariableforthe

principleanalysis,whichinvestigatedlisteners’abilitytodistinguishspeechproducedby

childrenwithASDfromspeechproducedbychildrenwithtypicaldevelopment.Listeners’

confidenceintheirtypicalityjudgmentswerealsoanalyzedasafunctionofspeakergroup.

Thesewerestandardizedwithinlistenerusingaz-transform,thenaveragedacross

listenersandwithinspeakertoobtainthemeanlistenerconfidenceratingperspeaker.


17

Theprincipleanalysesusedamixed-designANOVAtoassessthebetween-subjects

effectofspeakergroup(ASDversustypical)andwithin-subjectseffectofspeechcondition

(filteredversusunaltered)onthedependentvariables:residualized“disordered”

judgmentsandstandardizedconfidenceratings.AShapiro-Wilktestindicatedthatvalues

associatedwiththesedependentvariableswerenormallydistributed.Asignificanteffectof

groupon“disordered”judgmentswouldindicatethatlistenerscandistinguishchildren

withASDfromtheirtypicallydevelopingpeersbasedonspeechpatternsalone.An

interactionbetweengroupandspeechconditionwouldindicatetheinfluenceofnon-

prosodicfactorson“disordered”judgments.Speaker’sage-in-monthsandstandardized

PPVTscoreswereincludedascovariatesintheanalysestocontrolfortheireffectsonthe

dependentvariables.

Results

ListenerResponsesbyJudgmentTaskandSpeakerGroup

Theuntransformedandunstandardizedresponsesacrossthedifferenttaskswere

notthefocusofanalysis,butaresummarizedinTable3togivethereaderafullersenseof

thedata.Notethatcumulative“disordered”scoreswerehigheronaverageforchildren

withASDcomparedtotheirtypicallydevelopingpeersacrossalltasks.Notealsothatthe

meandifferencebetweenthetwogroupsofchildrenwasespeciallylargeintheunaltered

speechtask.


EffectofSpeakerGrouponResidualizedJudgmentsofDisorder

Recallthattoinvestigatetheinfluenceofspeechpatternsonjudgmentsabsentthe

influenceoflanguageweregressedthescoresobtainedfromthecontroltasks


18

(comprehensionandtext-basedjudgments)againstthescoresobtainedfromthe

experimentaltasks(filteredspeechandunalteredspeechjudgments).Theanalysisonthe

residualsindicatedthatlistenersweremorelikelytojudgespeechproducedbychildren

withASDas“disordered”thanspeechproducedbychildrenwithtypicaldevelopment,F(1,

30)=4.56,p=.041,ηp2=.132.Thiseffectofgroupinteractedwithcondition,F(1,30)=

4.52,p=.042,ηp2=.131,inthatlistenerswerebetterabletodistinguishbetweenASDand

typicallydevelopingchildrenintheunalteredconditionthaninthefilteredcondition(see

Figure1).Thesimpleeffectofconditionwasnotsignificant.

InsertFigure1abouthere.

Giventhesignificantinteractionbetweenconditionandgroup,andtheseemingly

weakeffectofgroupon“disordered”judgmentsinthefilteredspeechcondition(Figure1),

followupanalyseswereconductedtodeterminewhetherlistenerswereinfactableto

distinguishchildrenwithASDfromtheirtypicallydevelopingpeersinthefilteredspeech

condition.Thedataweresplitbyconditionandtheeffectofgrouponresidualized

“disordered”judgmentswastestedagain.Theresultswerethatlistenersdistinguished

betweengroupsofchildrenbasedonspeechpatternsintheunalteredspeechcondition,

F(1,30)=5.99,p=.020,ηp2=.166,butnotinthefilteredspeechcondition,F(1,30)=0.70,

p>.1.Notethattheeffectofgroupon“disordered”judgmentsintheunalteredspeech

conditionissignificantevenwhenalphaiscorrectedformultiplecomparisons(i.e.,the

Bonferronicorrectedalphais.025).

WrittenFeedbackfromListenersontheirJudgments

Again,theeffectsoflanguagewerecontrolledintheunalteredspeechconditionby

partiallingoutvarianceinjudgmentsduetowordchoice,syntacticstructure,andso.Thus,


19

theresultsshowninFigure1indicatethatlistenersdifferentiatedchildrenwithASDand

prosodicdisorderfromtheirtypicallydevelopingpeersbasedonspeechsoundpatterns

alone.Yet,therewasnoeffectofgroupontheresidualized“disordered”judgmentsinthe

filteredspeechcondition.Thissuggestseitherthatprosodicdifferencesbetweenthetwo

groupsofchildrenweresubtleatbestandlistenersonlygainedsensitivitytothose

differencesastheexperimentprogressedorthatlistenersattendedtosomethingother

thanprosodywhenmakingjudgmentsofdisorder.Listenerfeedbacksuggestedboth

explanationscouldbetrue.Specifically,listenersreportedattendingtoarticulation,speech

clarity,fluency(=flow,rate,rhythm),andaccenting(=wordemphasis,intonation)when

makingjudgments.Fluencyandaccentingareclearlyprosodicinnature;articulationand

speechclarityreferencesegmentalcharacteristics.Table4summarizesthefeedbackwe

obtainedfromeachofthe16listenerswhoprovidedjudgmentsonthefilteredand

unalteredspeechsamples.


Listeners’ConfidenceintheirJudgments

Theanalysisonlisteners’standardizedconfidenceratingssupportthesuggestion

thatthespeechsamplesobtainedfromchildrenwithASDweresubtlydifferentfromthose

obtainedfromtypicallydevelopingchildren.Theymayalsohavebeenmorevariable.

Specifically,therewasasignificanteffectofgrouponlisteners’standardizedratings,F(1,

30)=10.75,p=.003,ηp2=.264,asshowninFigure2.Listenerswerelessconfidentintheir

judgmentsofspeechproducedbychildrenwithASDthanintheirjudgmentsofspeech

producedbychildrenwhoweretypicallydeveloping.Therewasnoeffectofconditionor

anyinteractionbetweenconditionandgroup.


20


Discussion

TheresultsfromExperiment1indicatethatlistenerscorrectlyidentifyspeech

producedbychildrenwithASDas“disordered”moreoftenthanspeechproducedby

typicallydevelopingchildren.Thesoundpatterndifferencesaresufficientlysalientthat

listenerscandistinguishthegroupsoutsidethesocial-interactionalcontextandbasedon

veryshortspeechsamples.Yet,theabsenceofagroupeffectonjudgmentsinthefiltered

speechconditionsuggeststhatthesoundpatterndifferencesaresubtleenoughtobe

obscuredindegradedspeech.Thissuggestionisfurthersupportedbylisteners’weaker

confidenceintheirratingsofatypicalchildren’sspeechcomparedtotypicalchildren’s

speech.Listeners’weakerconfidenceintheirratingsofatypicalspeechmayalsoindicate

thatthesamplesprovidedbychildrenwithASDweremorevariablethantheonesobtained

fromtheirtypicallydevelopingpeers.

EXPERIMENT2

ThegoalofExperiment2wastotestwhetherlisteners’socialevaluationofspeakers

basedonspeechsoundpatternsalsodifferentiateschildrenwithASDfromtheirtypically

developingpeers.Thisgoalisinserviceofourquestionaboutwhetheratypicalspeech

soundpatternsmatter,wherethenotionofwhatmattersisunderstoodasaquestionabout

theeffectsofdifferenceonlisteners’attitudetowardsthespeaker.Therelationship

betweenlaylisteners’judgmentsofdisorder(Experiment1)andtheirlikeabilityratings

wasalsodirectlyexplored.


21

Methods

Participants

Twelvenewcollege-agedadultsprovidedlikeabilityratingsonthespeechsamples

fromExperiment1.Theseadultswererecruitedfromintroductorypsychologyand

linguisticsclasses,andreceivedcoursecreditfortheirparticipation.Allreportednormal

hearingandEnglishastheirnativelanguage.

RatingTask

ListenersratedboththefilteredandtheunalteredspeechsamplesfromExperiment

1forlikeabilityona7-pointLikertscale.Thelowvalueonthescalewasanchoredwitha

positivesocialstatement(“1=Awesome!Lovethiskid.”)andthehighvaluewithanegative

socialstatement(“7=Nah.Wouldn’tlikethiskid.”).Listenerssatinfrontofacomputer

monitorwiththeanchorsdisplayedabovetheratingscale,whichwasrepresentedasa

numberedsequenceof7buttons.Theylistenedtoaspeechsampleoverheadphones,rated

italongthelikeabilityscale,clicked“OK”andadvancedtoanewscreenandanewsample.

AsinExperiment1,listenerscompletedthefilteredspeechconditionbeforetheunaltered

speechcondition.Speechsampleswereplayedindifferentrandomorders.Listenerswere

toldonlythatthechildrenwerebetween5and11yearsold.UnlikeinExperiment1,they

werenottoldthathalfofthechildrenwerereceivingspeechandlanguagetherapyinthe

schools.

Analyses

Likeabilityratingswerestandardizedwithinlisteneracrossconditionsby

convertingtheratingscoresintoz-scores.Ratingswerethenaveragedacrosslistenersand

withinspeakers.Amixed-designANOVAwasusedtoassessthebetween-subjectseffectof

speakergroup(ASDversustypicaldevelopment)andwithin-subjectseffectofspeech


22

condition(filteredversusunaltered)onlikeabilityratings.Asignificanteffectofgroupon

likeabilityratingswouldindicatethatlistenersevaluatechildrenwithASDdifferentlyfrom

theirtypicallydevelopingpeersbasedonspeechpatternsalone.Aninteractionbetween

groupandspeechconditionwouldindicatetheinfluenceofnon-prosodicfactorson

listeners’ratings.Speaker’sage-in-monthsandstandardizedPPVTscoreswereincludedas

covariatesintheanalysestocontrolfortheireffectsonthedependentvariable.

Asecondanalysisusedlinearregressiontoinvestigatetherelationshipbetweenthe

residualized“disordered”judgmentsfromExperiment1andthelikeabilityratings

obtainedfromadifferentgroupoflistenersinExperiment2.Likeabilityratingswerethe

dependentvariable,andjudgmentsofdisorderthepredictorvariable.Age-in-months,

PPVTscores,andspeechconditionwereenteredascontrolpredictorvariables.

Results

EffectofSpeakeronLikeability

Theanalysisindicatedasignificantinteractionbetweengroupandspeechcondition,

F(1,30)=5.17,p=.030,ηp2=.147,whichisshowninFigure3.Neitherthesimpleeffectof

groupnorthatofspeechconditionwassignificant,thoughtheeffectofgroupapproached

significance(p=.051).


Giventheinteraction,theeffectofgroupwasexploredfurtherinanalysessplitby

condition.Theseanalysesindicatedasignificanteffectofgrouponlikeabilityratingsinthe

unalteredspeechcondition,F(1,30)=6.79,p=.014,ηp2=.184,butnotinthefiltered

speechcondition.AsshowninFigure3,childrenwithASDwereperceivedassignificantly

lesslikeablethanchildrenwhoweretypicallydevelopingbasedontheunalteredspeech


23

samples1.Notethattheeffectissignificantevenwhenalphaiscorrectedformultiple

comparisons(i.e.,theBonferronicorrectedalphais.025).

RelationshipbetweenJudgmentsofDisorderandLikeability

TheresultsonlikeabilityrecallthosefromExperiment1inthatlistenersonly

discriminatedbetweenthegroupsofspeakersintheunalteredspeechcondition.The

similaritybetweenthetwoexperimentswasconfirmedinalinearregressionanalysis,

whichshowedthattheresidualizedjudgmentsofdisordercouldbeusedtoexplain/predict

likeabilityratings,β=.59,t(67)=6.01,p<.001,evenwithage-in-months,PPVT,and

speechconditioncontrolledinthemodel.Byitself,thepredictor“disordered”judgments

accountedfor42%ofthevarianceinlikeabilityratings.Noneofthecontrolvariables

explainedasignificantproportionofthevariance.

TherelationshipbetweenperceiveddisorderandlikeabilityisshowninFigure4.

Speechsamplesthatelicitedahigher“disordered”responseelicitedamorenegativesocial

evaluation(“Nah.Wouldn’tlikethiskid.”).Whensplitbyspeechcondition,wefindthatthe

correlationbetweenthejudgmentsofdisorderandlikeabilityratingswasstrongerinthe

unalteredspeechcondition,r(34)=.72,p<.001,comparedtothefilteredspeechcondition

r(34)=.48,p=.004,thoughthisdifferencewasnotsignificant,z=1.51,p=.066(one-

tailed).

1Recallthatthe7-pointlikeabilityscalewasanchoredsuchthathigherscoresindicateamorenegativesocialevaluationthanlowerscores(“1=Awesome!Lovethiskid.”versus“7=Nah.Wouldn’tlikethiskid.”).


24


Discussion

TheresultsfromExperiment2indicatethatlaylistenersevaluatechildrenwithASD

morenegativelythantheirtypicallydevelopingpeers.Thus,likeinExperiment1,listeners

wereabletodistinguishbetweenspeakersbasedontheshortspeechsamplesprovided.

TheresultsalsoparallelthosefromExperiment1inthatlistenerswerenotableto

distinguishbetweenthedifferentgroupsofspeakersinthefilteredspeechcondition.A

regressionanalysisconfirmedthatthesimilaritiesbetweenExperiment1andExperiment

2wereduetoasignificantcorrelationbetweenlaylistenersjudgmentsofdisorderand

theirsocialevaluationofchildren.Next,weinvestigatewhetherthiscorrelationmeansthat

thesamesoundpatternstriggerboththeperceptionofdisorderandanegativesocial

evaluation.

EXPERIMENT3

InExperiment3,furtherperceptualevaluationofchildren’sspeechandacoustic

measuresofsegmentalandsuprasegmentalfeatureswereusedtoidentifythespeech

soundpatterningthatmediatedlisteners’judgmentsof“typical”versus“disordered”in

Experiment1andtheirlikeabilityratingsinExperiment2.Thegoalwastoanswerthe

questionofwhetherbothtypesofjudgmentsreferencethesamepatternsinorderto

understandwhyajudgmentofdisordermayleadtoanegativesocialevaluation.Thus,the

focusofExperiment3isonlisteners’behavior.Wedonotinvestigatethisbehaviorasa

functionofthespeakergroups,butdoconfirmthatchildrenwithASDdifferfromtypically

developingchildrenalongtheperceptualandacousticdimension(s)thatpredictjudgments

ofdisorderandtheirlikeabilityratings.


25

Methods

Participants

Sixteennewcollege-agedadultsratedtheunalteredspeechsamplesalongseveral

dimensions.Theseadultswererecruitedfromintroductorypsychologyandlinguistics

classes,andreceivedcoursecreditfortheirparticipation.Allreportednormalhearingand

Englishastheirnativelanguage.

RatingTask

ListenersratedtheunalteredspeechsamplesfromExperiment1and2ona7-point

Likertscalealongthe5dimensionsderivedfromthesubjectivefeedbackacquiredin

Experiment1:articulation,speechclarity,fluency,andaccenting.Afifthdimension,

monotony,wasincludedtodifferentiateratingsthatmayhavebeenduetodifferences

appropriatelypitchaccentinglinguisticcontent(i.e.,tune-to-textalignment)fromthose

duesimplytopitchvariability.Listenerswereonlytoldthattheywouldberatingchildren’s

speechalongdifferentperceptualdimensions.Listenerswerealsotoldtheagerangeof

childspeakers,butnomentionwasmadeofthefactthatsomeofthechildrenwere

receivingspeechandlanguagetherapyintheschools.Thespeechsampleswereexplained

asbeforewithreferencetotheelicitationmethod.Onlyunalteredspeechsampleswere

usedinExperiment3becausetheseelicitedthehighestcorrelationsbetweenjudgmentsof

disorderandlikeability(seeExperiment2),andbecauseweneededtolimitthenumberof

stimulipresentedtolistenersinorderforthemtoratealldimensionswithinthe45to55

minutesallottedto“workwithbreaks”duringtheexperiment.

Listenerssatinfrontofacomputermonitorwiththeanchorsdisplayedabovethe

ratingscale,whichwasrepresentedasanumberedsequenceof7buttons.Thelowvalue

onthescalewasanchoredwithadescriptionoftypicalspeechandthehighvaluewitha


26

descriptionofatypicalspeech.Thelowandhighanchorsforarticulationwere“1=ALL

soundscorrectlyproduced”and“7=NOsoundscorrectlyproduced;”forclearness,“1=

ExtremelyClear”and“7=TotallyUnclear;”forfluency,“1=SuperFluent”and“7=Really

Disfluent”.Theanchorsforaccenting2were,respectively,“1=EmphasizesMostImportant

Words”and“7=EmphasizesOnlyIrrelevantWords;”andformonotony,“1=VeryLively”

and“7=TotallyMonotonous.”Listenersheardaspeechsampleoverheadphones,ratedthe

sampleonthescalealongthespecifieddimension,clicked“OK”andadvancedtoanew

screenandanewsample.Thereweretworepetitionsofeachsampleasbefore.Allsamples

werepresentedinrandomorder.Theorderinwhichdimensionswereratedwasvaried

acrosslisteners.Fourteenlistenerscompletedratingsalongthearticulationdimension3.All

listenerscompletedratingsalongallotherdimensions.

AcousticMeasurements

Inordertobettercharacterizespeechsoundpatterningrelevanttothedimensions

ofarticulation,speechclarity,fluency,accenting,andmonotony,anumberofacoustic

segmentalandsuprasegmentalmeasuresweretakenonthe136utterancesthatwerethe

speechsamplesprovidedtolisteners.Measurementswerebasedonthehand-

segmentationoftheutterancesintoconsonantandvowelintervalsinPraatusingstandard

segmentationcriteria(see,e.g.,Redford,2014).Voweldurations,F0,F1,andF2were

automaticallyextracted.ThemeasurementintervalforF0wassetat.01secondsandthe

2Theanchorsforratingalongtheaccentingdimensionweremeanttodrawlisteners’attentiontotheintonationalaspectsofthephrase,andespeciallytotheappropriate/inappropriateuseofprosodicfocus,followingtheliteratureonprosodicdeficitsinspeechproducedbyindividualswithASD.3Listenerswererun2atatimeinthelaboratory.Ononeoccasion,theexperimentalsessionstartedlateandsothelistenerswhoparticipatedinthatsessionwerenotabletocompletethetaskintime.Sincetaskorderwasvariedacrosssessions,bothlistenersintheshortenedsessionwereunabletocompletethesame/lasttaskinthesession.


27

rangesetfrom75to600Hz.ValuesthatdeviatedoneSDfromaspeaker’smean,werere-

measuredbyhand.VowelformantmeasureswerebasedonthePraatLPCalgorithmin

timestepsequalto10percentofthevowelinterval,andwiththemaximumnumberof

formantssetto5andmaximumformantfrequencyto6000Hz.Everyformanttrackwas

visuallyinspected,thenhand-correctedandre-measuredifthetrackswereoff.

Segmentalmeasures.Voweldurationandformantmeasureswereusedtoderive3

measuresofarticulation:schwaduration,meannormalizedvariabilityinschwaduration,

andF1xF2vowelspace.Voweldurationandstabilityinrepeatedvowelproductionare

indicatorsofspeechmotorcontrol,withshorterdurationsandmorestableproductionsa

featureofgreatercontrolovertargetedarticulations(seeRedford&Oh,2017).Schwa

vowelsareminimallyinfluencedbyprosodicfactorssincetheydonotreceivelexicalstress

orphrasalaccents,someanschwadurationandvariabilityindurationislesssensitiveto

contexts.Therewerealsomultipleschwaproductionsineveryspeechsample,soschwa

durationandvariabilitywassomethingwecouldcalculateforallspeakers.TheF1xF2

vowelspacewasdefinedbyfullvowelsthatwerealsomonopthongs.Thespacewas

calculatedasthemeanEuclidiandistanceofeachfullvowelfromthemeanfullvowelin

eachutterance.Thismeasurethusprovidesinformationaboutvoweldistinctivenesswithin

anutterance,whichisacorrelateofspeechclarity(see,e.g.,Lindblom,1990).

Suprasegmentalmeasures.ThedurationandF0measureswereusedtoderive

measuresofrate,rhythmandintonation.Articulationratewascalculatedasnumberof

syllablespersecondofspeech,excludinganysilencesduetopausing,whichwasextremely

rareinanycase(seespeechsamplesunderExperiment1).Thecoefficientofvariationin

voweldurations(i.e.,standarddeviation/mean)wasusedtocapturespeechrhythm.This

measurehasbeenproposedintheliteratureasaneffective,simple-to-compute,rate-


28

normalizedrhythmmetric(White&Mattys,2007).Finallengthening,afeatureofprosodic

boundarymarking,wascalculatedastheratioofphrase-finalvoweldurationtothe

averagenon-finalvowelduration.Anotherfeatureofprosodicboundarymarking,final

pitchchange,wascalculatedasF0changefromthepenultimatetoultimatesyllableofthe

phrase.Pitchdeclination,acharacteristicofthewholeintonationcontour,wascalculated

astheslopeofabestfitregressionlineplottedthroughsequentiallyarrangedF0valuesfor

eachutterance.

Inadditiontothesegmentalandsuprasegmentalmeasures,severalacoustic

measurescorrespondingtovoiceweretakentodeterminewhetheroverallvoicequality

mighthavecontributedtolistenersjudgmentsofdisorder(see,e.g.,Shribergetal.,2001).

ThemeasuresweremeanF0andtwomeasuresoftheproportionoftimeduringaglottal

periodwherethereisnocontactbetweenthevocalfolds,whichisrelatedtovocalquality

rangingfromvocalfrytobreathy.These“openness”measureswerethemeanamplitude

differencebetweenthefirstharmonic(H1)andthesecondharmonic(H2)acrossallvowel

intervals,andorthemeanamplitudedifferencebetweenH1andthefirstformant(A1)(see

Garellek&Keating,2011).AswiththeF0andformantvalues,phonationmeasureswere

calculatedautomaticallyusingaPraatscript.F0andformantcalculationsweresetas

before.

DataReduction

Ratingsalongeachdimensionwerestandardizedwithinlistenerbyconvertingthe

Likertscoresintoz-scores.Ratingswerethenaveragedacrosslistenersandwithin

speakers.Inter-correlationsbetweentherateddimensionswereassessed.Ratingsalong

thedimensionsofarticulation,clearness,andfluencywereexceptionallyhighlycorrelated,

withcorrelationcoefficientsrangingfrom.92(articulationandfluency)to.96(articulation


29

andclearness).Accordingly,these3dimensionswerereducedtooneusingprincipal

componentsanalysis(PCA).ScoresfromthefirstfactorofthePCAweresavedandusedin

placeofthearticulation,clearness,andfluencyratings.Foreaseofreference,wewillrefer

tothesescoresascapturingthedimensionofintelligibility.Thisdescriptivelabelwas

chosenbecausetheconstituentcomponentsofthisshareddimension(e.g.,articulation,

clearness,andfluency)areallattributesofintelligiblespeech.Intelligibility,accenting,and

monotonywerethenenteredintoamultipleregressionmodeltopredictjudgmentsof

disorder(seebelow).Thismodeldidnotsufferfromunacceptablecollinearity(VIF<3.5).

Inter-correlationsbetweentheacousticmeasureswerealsoassessed.Manydidnot

reachsignificance.AllandonlytheonesthatdidareshowninTable5.Notethenear

perfectcorrelationbetweenthetwomeasuresrelatedtovoicequalityinthetable.Given

thehighdegreeofoverlap,thesemeasureswerereducedtooneusingPCA.Scoresfromthe

firstfactorofthePCAweresavedandusedinplaceoftheindividualH1-H2andH1-A1

measures.Foreaseofreference,wewillrefertothesescoresasmeasuresofvoicequality.


StatisticalAnalyses

Stepwiselinearregressionmodelingwasusedtoinvestigatetherelative

contributionoflistener-identifiedperceptualdimensionsofspeechsoundpatterningto

residualized“disordered”judgmentsandz-scoredlikeabilityratingsonunalteredspeech

samples.Age-in-monthsandreceptivevocabularyscoreswereincludedascontrol

variablesinthemodel.Backwardeliminationwasusedtoreducethenumberofpredictor

variablestoonlythosethatcontributedsignificantlytoexplaininglisteners’responses.The


30

sametechniquewasthenusedtocharacterizeinacoustictermstheperceptual

dimension(s)thatbestexplainedlisteners’behaviorinExperiments1and2.

Results

PerceptualBasisforJudgmentsofDisorder

Thefullmodelaccountedfor69%ofthevarianceinjudgmentsofdisorderandhad

anadjustedR2of.63.Thesignificantmodelwiththefewestpredictorsaccountedfor67%

ofthevarianceandhadanadjustedR2of.65.Theonlysignificantpredictorsinthismodel

wereage-in-months,β=.22,t(33)=2.10,p=.045,andintelligibility,β=.84,t(33)=7.98,p

<.001;thatis,theperceptualdimensionderivedfromtheoverlapinratingsofarticulation,

clearness,andfluency.Whereasintelligibilitybyitselfaccountedfor63%ofthevariancein

“disordered”judgments,themodelwithage-in-monthsalonewasnobetterthanthenull

modelataccountingforvariance.Figure5showstherelationshipbetweenpoor

intelligibility4and“disordered”judgments.


Anindependentsamplest-testconfirmedthatvariancealongtheintelligibility

dimensionalsovariedsystematicallywiththegroupofspeakerswhoproducedthe

samples,MeanDifference=1.02,t(33)=3.40,p=.002(two-tailed).Althoughchildrenwith

ASDwereratedaslessintelligibleonaveragethantheirTDpeers,itisalsoevidentfrom

thedatapresentedinFigure5thatnotallchildrenwereratedasequallyunintelligiblenor

weretheyallratedasequally“disordered”.

4Recallthatthe7-pointratingscalewasanchoredsuchthathigherscoresaremorecompatiblewithdescriptionsofdisorderedspeech.(e.g.,“1=ALLsoundscorrectlyproduced”versus“7=NOsoundscorrectlyproduced”).


31

PerceptualBasisforLikeabilityRatings

Thefullmodelaccountedfor57%ofthevarianceinlikeabilityratingsandhadan

adjustedR2of.49.Thesignificantmodelwiththefewestpredictorsaccountedfor49%of

thevarianceandhadanadjustedR2of.46.Theonlysignificantpredictorsinthismodel

wereintelligibility,β=.56,t(33)=4.12,p<.001,andmonotony,β=.29,t(33)=2.15,p=

.040.Intelligibilityaccountedfor42%ofthevarianceinlikeabilityratingsbyitself,and

monotonyfor21%.Thus,itwouldseemthatintelligibilityandmonotonyeachaccounted

forsomeofthesamevarianceintheregressionmodel.Figure6showstherelationship

betweenintelligibilityandlikeability,wherehighervaluesalongeachaxisindicatemore

negativeevaluations.


AcousticCharacterizationofIntelligibilityandMonotony

Segmental,suprasegmental,andvoicemeasureswereenteredaspredictorvariables

inastepwiseregressionmodelstoprovideacousticcharacterizationsoftheperceptual

dimensions,intelligibilityandmonotony.Thefullmodelsaccountedfor46%ofthe

varianceinintelligibilityandfor68%ofthevarianceinmonotony;theyhadadjustedR2sof

.20and.55,respectively.Thesignificantmodelswiththefewestpredictorsaccountedfor

41%ofthevarianceinintelligibilityandfor56%ofthevarianceinmonotony;theyhadan

adjustedR2sof.17and.50,respectively.Articulationratewasthesolesignificantpredictor

ofintelligibility,β=–.41,t(33)=–2.55,p=.016:slowerrateswereassociatedwithpoorer

intelligibility.Bycontrast,thereducedmodelofmonotonyincludedtwosignificant

segmentalmeasures—meanschwaduration,β=.31,t(33)=2.54,p=.016,andvowel

distinctiveness,β=–.25,t(33)=–2.04,p=.050—andtwosignificantvoicemeasures—


32

meanF0,β=–.37,t(33)=–2.45,p=.020,andvoicequality,β=.44,t(33)=2.91,p=.007.

Thedirectionoftheeffectofschwadurationisconsistentwiththeeffectofspeechrate:

longerschwawereassociatedwithgreaterperceivedspeechmonotonythanshorter

schwas.Theeffectofvoweldistinctivenessindicatesthatmoremonotonousspeechwas

alsolikelylessclear.Lowerpitchandlessmodal(morebreathy)voicequalitieswerealso

associatedwithmoremonotonousspeech.Giventhislistofsignificantpredictorvariables,

itwouldseemthatalthoughtheperceptualdimensionsofintelligibilityandmonotonyare

acousticallyseparable,botharewell-characterizedbyfeaturesthataremoreassociated

withspeechmotorandvoicefactorsthanwithlinguisticprosody.

Discussion

TheresultsfromExperiment3stronglysuggestthatlaylistenersattendtopatterns

relatedtomotorspeechratherthantoprosodiconeswhentheyareaskedtoclassify

children’sspeechsoundpatternsas“disordered”or“typical”andtoevaluatehowmuch

theylikeachildbasedonshortspeechsamples.Thisconclusionisbasedonthefindingthat

“accenting,”themostovertlyprosodicperceptualdimensionevaluated,wasnota

significantpredictorofjudgmentsofdisorderoroflikeability.Moreover,thestrongest

predictorofbothperceiveddisorderandlikeabilitywasintelligibility,adimensionderived

fromtheoverlapinratingsofarticulation,clarity,andfluency.Thisdimensionwasbest

characterizedbyarticulationrate.Ratemaybeasuprasegmentalfeatureofspeech,butitis

onemoretypicallyassociatedwitharticulatorytimingcontrolthanwithprosody(see,e.g.,

Redford,2014).Similarly,thedimension“monotony”wasbestcharacterizedbymeasures

thatcapturedtheaccuracyandspeedofsegmentalarticulations(schwadurationand

voweldistinctiveness)andbymeasuresrelatedtovoicecharacteristics(pitchandvoice

quality)thatarealsooutsidethedomainofprosody,strictlydefined.


33

GENERALDISCUSSION

AlthoughchildrenandadultswithASDareoftenreportedtohaveatypicalspeech

patterns,manyindividualswithautismshownoprosodicdeficits(seeShribergetal.,2001;

2011;Nadig&Shaw,2012).Moreover,thebehaviorsthatarecentraltoestablishinga

diagnosisofautismaremoreobviouslysociallydisabling(e.g.,notrespondingtoone’sown

name)anddeviant(e.g.,echolalicspeech)thanwemightimagineunusualspeechpatterns

tobe.Thecurrentstudywasmotivatedbythequestionofwhetheratypicalspeechpatterns

inchildrenwithASDisimportantenoughtowarrantresearch.Inaclinicaloreducational

context,thenotionofwhatbehaviorisorisnotimportanttounderstandamountstoa

questionabouttheeffectsthatsuchbehaviorhasonpeerrelationsoronlearning.The

resultsfromthepresentstudyprovideevidenceinsupportoftheviewthatatypicalspeech

soundpatternsmarkchildrenwithASDasdifferentfromtheirTDpeers,andarelikelyto

createbarrierstopositivesocialinteractions.Weconcludefromthisthatatypicalspeech

shouldbeaddresseddirectlyinchildrenwithASD.Theresultsdonot,however,support

theviewthatprosodyshouldnecessarilybethefocusoftheseefforts.Wheninputis

limited,listeners’judgmentsareinfluencedbyspeechpatternsthatlikelyreflectdelayedor

deviantspeechmotorcontrolandunusualvoicequalityratherthanprosodicdeficitsper

se.Morespecifically,thecurrentstudyidentifiesintelligibilityastheprimaryperceptual

dimensionthatmediatesbothlisteners’judgmentsofdisorderandtheirsocialevaluation

ofthechildbasedonshortsnippetsofspeech.Thisdimensioniscloselyassociatedwiththe

perceivedgoodnessandfluency(=speed)ofsegmentalarticulation.

Intelligibilityisaconceptfundamentaltostudiesofmotorspeechdisorders(e.g.,

dysarthria),whereitisusuallymeasuredasthenumberofdistinctspeechsoundsorwords

recognizedbyapaneloflisteners(seee.g.,Kentetal.,1989).Wewouldthereforeliketo


34

clarifythatnoneofthechildrenwhoparticipatedinthepresentstudysoundeddysarthric.

Theirspeechwasnotdistorted,justdifferentsounding.Thisdifferencewascharacterized

bythereferringSLPsasunusualprosody,butlisteners’behaviorsuggeststhatperhaps

speechmotorfactors,ratherthanlinguisticprosodicones,weremoreimportanttothe

perceptionofdifference.Itisforthisreasonthatwewouldarguethatthenotionof

intelligibilitybettercaptureswhatlistenersweremostsensitivetowhendistinguishing

childrenwithASDfromtheirtypicallydevelopingpeersbasedontheshortspeechsamples

provided.Additionalevidenceforthisviewcomesfromthefeedbackthatlisteners

providedinExperiment1.Forexample,Listeners1,2,and15allnotethattheirjudgments

wereaffectedbywhattheyperceivedas“slurred”or“slurring.”Listeners11and13refer

totheinfluenceofa“lisp”ontheirjudgments.Listeners3,4,5,7,8,11,and15commenton

aspectsofrate.Relatedly,articulationratewasasignificantpredictorofintelligibility.

Elsewhere,wehavefoundelsewherethatdefaultarticulationratesindextheacquisitionof

articulatorytimingcontrolmorebroadly,atleastintypicallydevelopingchildren(Redford,

2014).

Theconclusionthatlistenersmayhavefocusedonspeechmotorfactorsto

distinguishbetweenchildrenwithASDandTDisatoddswiththecharacterizationof

autisticspeechasprosodicallydisorderedifoneunderstandsspeechprosodyinlinguistic

terms;thatis,asasystemofmetricalgroupingandaccentplacementsgovernedbya

prosodicgrammarthatislinked,atsomelevel,tosyntacticstructureandsemantic-

pragmaticmeaning.Deficitsinlexicalstressplacementandcontrastivefocusmeetthis

definitionofprosodyandsoareconsistentwiththeprimarydeficitsinsemantic-pragmatic

communicationthatisassociatedwithASD,butthesewerenotfoundhere.Moreover,the

differenceswedidfindcorrespondtothemanyotherdocumenteddifferencesbetween


35

autisticspeechandtypicalspeechthatarenotnecessarilyprosodic.Inparticular,acoustic-

phoneticstudiesthatcharacterizedifferencesbetweenASDandtypicalspeechintermsof

globaldifferencesinpitchrangeandvariability(Diehletal.,2009;Nadig&Shaw,2012),

longerwordandutterancedurations(Diehl&Paul,2012),andhigherratesofdisfluencies

(Shribergetal.,2001)areallcompatiblewithdifferencesinplanningandproductionand

notwithprosodyperse.

Thefindingsthatlistenersaresensitivetospeechintelligibilitywhenjudgingshort

snippetsofspeechandthatthissensitivityaffectstheirsocialevaluationofaspeakeralso

hasimplicationsforconceptualizingthesemantic-pragmaticimpairmentsinchildrenwith

ASD.Inparticular,afocusonintelligibilityemphasizestheimportanceofthesocial

interactionfordefining“impaired”,“atypical”or“disordered”,andsosupportsaviewof

pragmaticimpairmentasemergentfromtheinteractionbetweenspeakersandlisteners

(seePerkins,2007).Whenthecontributionsofbothareinbalance,communicationis

successfulandpragmaticsareintact.Whenonememberofthedyadmustadaptinan

unfamiliar,asymmetricalmannertoaccommodatetheother’sbehavior,then

communicationsuffersandpragmaticsisimpaired.Thisviewofimpairmenthasthe

advantageofallowingustounderstandwhylisteners’perceptionofdisordermightaffect

theirsocialevaluationofthespeaker.Anydecrementinspeechintelligibilityislikelyto

resultincommunicativeasymmetry;namely,anasymmetrythatcreatesextraworkforthe

listener.Iflisteners(implicitly)resentdoingextrawork,thentheymayblamethespeaker.

NotethatthisexplanationissimilartothatwhichRiceandcolleaguesproposedtoexplain

theirfindingsthatchildrenwithspecificlanguageimpairmentorwhoaresecondlanguage

speakersofEnglishhavelessaccesstopositivesocialinteractionsthantheirtypically


36

developingandnativeEnglish-speakingpeersinUSschools(Riceetal.,1991;Gertneretal.

1994).

Althoughwehavesuggestedthatlistenersaremoresensitivetospeechsound

patternsthatsuggestdeficitsinspeechmotorcontrolratherthaninprosody,itis

importanttonotethatthestrengthofthisconclusionislimitedbytheexperimentaldesign

weused.Specifically,theshort,decontextualizedspeechsamplespresentedtolisteners

mayhaveforcedthemtolatchontosomethingotherthanprosodytomaketheirdecisions.

Ifunusualprosodyinautismoftenreflectsinappropriateorincorrectprosodicfocus

(Shribergetal.,2001;Paul,Augustyn,etal,2005;Peppéetal.,2007),thenaccessto

languagecontextwouldbecriticalforlistenerstoidentifytheatypicalpatterns.Infact,one

waytointerpretthefindingthatlistenerscouldonlydistinguishchildrenwithASDfrom

theirtypicallydevelopingpeersintheunalteredspeechconditionisthatonlythis

conditionprovidedlistenerswiththerelevantinformationabouttune-to-textalignment.

Moreover,somelistenersdidcommentthathowaspeakerusedaccentinginfluencedtheir

judgmentsofdisorder.Forexample,Listener4inExperiment1notedthattheirjudgment

wasaffectedbywhetherthechild“stressedtherightsyllables”andListener16was

sensitivetowhetherornotemphasiswasusedcorrectly.Futureworkshouldevaluatethe

relativeinfluencesofintelligibilityandungrammaticalprosodicfocusassignmentand

phrasingonlisteners’behaviorbyusinglongerstretchesofspeechthatprovideadiscourse

context.

Inconclusion,theresultsfromthepresentstudyshowthatlaylistenersare

sensitivetotheatypicalspeechpatternsproducedbychildrenwithASD.Thissensitivity

alsoinfluencestheirsocialevaluationofthespeaker.Speakerswhoproducedpatternsthat

wereperceivedasatypicalordisorderedandratedaslesslikeable.Thesefindingsvalidate


37

effortstounderstandandtreatatypicalspeechinASD,eveninthecontextofthemany

otherdisablingbehaviorsassociatedwiththedisorder.Thepresentstudyalsoaddstoa

bodyofliteratureonlistenersensitivitytosocial-indexicalaspectsofspeech,butsuggests

thatsomenegativebiasestowardsspeakersmayemergefromthemodelingeffortthatis

neededforlistenerstoengageinsuccessfulcommunicationwithanunfamiliarspeaker.


38

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43

TABLE1

CharacteristicsofparticipantswithSPEDeligibilitiesforreceivingspeechandlanguage

servicesintheschoolsunderASD.

Speaker Sex Age Symptoms Lg.Delay PPVTp109asd M 6;4 severe No 106

p110asd M 7;1 minimal Yes 119

p102asd M 7;9 severe Yes 126


p103asd M 8;1 moderate Yes 85

p107asd M 8;1 severe No 107

p108asd M 8;1 moderate Yes 112


p115asd M 8;10 severe No 86

p101asd F 9;3 moderate No 83

p111asd F 9;4 severe No 80





p113asd F 11;7 severe Yes 90



44

TABLE2

Characteristicsofparticipantswithtypicaldevelopment.

Speaker Sex Age PPVTp1032td M 6;4 112

p1037td M 7;2 121

p1061td M 7;7 90

p1073td M 7;11 106

p1011td M 8;0 117

p1083td M 8;0 147

p1045td F 8;1 129

p1072td M 8;2 114

p1016td M 9;0 134

p1058td F 9;2 103

p1075td F 9;4 88

p1026td M 9;5 110

p1027td M 9;7 129

p1006td F 10;0 111

p1010td M 10;1 111

p1001td F 10;10 135

p1022td M 10;10 130


45

TABLE3

Mean(andstandarddeviation)ofuntransformedandunstandardizedresponsesareshownas

afunctionofspeakergroup(TD=typicallydeveloping).Responsesofdisorderobtainedinthe

filteredspeech,unalteredspeech,andtext-basedjudgmenttaskswereaggregatedacross

samplesandlistenerstorenderaby-speakerperceiveddisorderscore(maximumscore=32

forspeech-basedjudgments;16fortext-basedjudgments).Comprehensionoffilteredspeech

wasratedona5-pointscale(nowordsunderstood=1;allwordsunderstood=5).Listeners

alsoratedhowconfidenttheywereintheirresponses(notatall=1;completelysure=5).

JudgmentTask Responsetype Childrenw/TD Childrenw/ASD

Filteredspeech(Experimental)

Cumulative“disordered” 12.53(7.08) 14.71(6.45)

confidence 3.27(0.31) 3.20(0.25)

Comprehension(Control)

ratingsfrom1to5 2.32(0.64) 2.10(0.50)

confidence 3.74(0.89) 3.61(0.91)

Unalteredspeech(Experimental)


confidence 3.67(0.32) 3.47(0.19)

Text(Control)


confidence 3.41(0.90) 3.38(0.93)


46

TABLE4

Summaryofindividuallistener’sresponsestotherequestforfeedbackonwhatspeech

characteristicsinfluencedtheirjudgmentsofdisorderinthefilteredandunalteredspeech

conditions.Theresponsesarecategorizedbymajortheme.

Listnr Articulation SpeechClarity Fluency Accenting

1 mispronoun-ciation

slurringofwords

fluidityand…fluctuation

appropriateflux…toaccent

2 slurredwords,concisepronunciation

choppy,flow,pausingatawkwardtimes

emphasisofaword,enthusiastic

3 clarity,unclearslowerspeech,streamingwords,rhythm

4 steadyrhythm,quickly,slowly,smoothly

stressedtherightsyllables,accents

5 enunciated slower,sortofflow upanddown,placedemphasis

6

distorted“r”and“l”sounds,oddlypronouncedblends

7 mispronouncedwords,sounds speechrate stresspatterns

8 slurred,clearer,easiertounderstand littleslower,faster enthusiasm

9 pausesbetween…phrases

mid-phraseinflections

10 soundeddisjoint emphasizecertainpoints,excitement

11 lisp,“r”sounds speakeffectively draggedtheirsyllablesout

12 muffled,extremelyunclear

13 lisp,pronounciating understand…clearly

14 naturalflow,rhythm,paceofwords tone,clashy

15 clearandprecise,slurred quickly

16 disorganizedtones,emphasizedfornopurpose


47

TABLE5

Allandonlysignificantpair-wisecorrelationsbetweenacousticmeasures.

SchwaDur.

Artic.Rate

F0Slope

FinalF0

MeanF0

H1–H2

H1–A1

SchwaDur. 1 –.43*

Artic.Rate 1 –.52** –.39*

F0Slope 1 –.41* –.44** –.53**

FinalF0Change 1

MeanF0 1 –.61** –.56**

H1–H2 1 .95**

H1–A1 1

*p<.05;**p<.001


48

FIGURELEGENDS

Figure1.Listeners’judgmentsofdisorder,absenteffectsoflanguage,areshownasa

functionofspeechconditionandspeakergroup(TD=typicallydevelopingchildren;

ASD=childrenwithASDandprosodicdisorder).

Figure2.Listeners’confidenceintheirjudgmentsofdisorderareshownasafunctionof

speechconditionandspeakergroup(TD=typicallydevelopingchildren;ASD=

childrenwithASDandprosodicdisorder).

Figure3.Listeners’ratingsofachild’slikeability(lowanchor=“Awesome!Lovethiskid.”;

highanchor=“Nah.Wouldn’tlikethiskid.”)shownasafunctionofspeechcondition

andspeakergroup(TD=typicallydevelopingchildren;ASD=childrenwithASDand

prosodicdisorder).

Figure4.Listeners’judgmentsofdisorderbasedonfilteredandunalteredspeechsamples

predictsanothergroup’slikeabilityratingsofthespeakerswhoproducedthose

samples.Lowvaluesalongthey-axisindicategreaterlikeabilitythanhighvalues.

Figure5.Theintersectionoflisteners’ratingsofthearticulation,clearness,andfluencyof

unalteredspeechsamples(=intelligibility)predictsanothergroup’sjudgmentsof

disorderbasedonthosesamespeechsamples.Text-basedjudgmentsofdisorder

arepartialledoutfromthevaluesshownalongthey-axis.

Figure6.Theintersectionoflisteners’ratingsofthearticulation,clearness,andfluencyof

unalteredspeechsamples(=intelligibility)predictsanothergroup’slikeability

ratingsofthespeakerswhoproducedthosesamples.Lowvaluesalongthey-axis

indicategreaterlikeabilitythanhighvalues.


49

FIGURE1


50

FIGURE2


51

FIGURE3


52

FIGURE4


53

FIGURE5


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FIGURE6

Documents

Lay listener classification and evaluation of typical and ... · Final version accepted for publication in Language and Speech June 6, 2017. Lay listener classification and evaluation