Intona&onalphonologyinBengaliandEnglishinfant-directedspeech

Kris&neYu,SameerudDowlaKhan&MeghaSundara

Underrevision:LabPhonology

Infant-directedspeech

•  Cross-linguis&cally,comparedtoadultdirectedspeech,infant-directedspeech(IDS)has–  slowerspeechrate–  shorteruHerances

–  highermeanfundamentalfrequency(F0),–  highermaximumF0,–  expandedF0range,–  greaterF0variability,

Whyf0-relateddifferencesinIDS?

•  ToregulateinfantaHen&onandaffect–  IDS=“unstructuredexaggera&onofthepitchcontour”•  Gradient,language-generalphone&cview

– Possiblealterna&ves•  IDS=“exaggera&onoftonaltargetsseeninADS”

–  Thatis,allophonicdifferencesinIDS–  Language-specificphone&cview

•  IDS=“differentchoiceoftonaltargetscomparedtoADS”–  Language-specificphonologicalview

Previousresearch•  Evidenceforunstructuredexaggera&on

–  Inalexicaltonelanguage,shouldinterferewithtransmissionofmeaning•  Poortoneiden&fica&oninThaiinuHerance-finalnotini&alposi&on(Kitamuraetal.,2002)

•  Evidenceforallophonicexpansionofpitchrange–  F0expansion,butnocompromisedtransmissionoftonaltargets

•  Mandarin(Liu,Tsao&Kuhl,2007);Cantonese(Xu,2008);Hakka(ChengandChang,2014)

–  F0expansion,butnocompromiseofboundarytones•  JapaneseIDS(Igarashi,Nishikawa,Tanaka,andMazuka,2013)

–  Expansionrestrictedtothemorevariableboundarytones,notthelessvariablepitchaccents

Thisstudy

•  CompareADSandIDSin2ways– Choiceoftonaltargets–  Implementa&onoftonaltargets

•  Boundarytonesandpitchaccent

Methods•  Comparedadult-andsimulatedinfant-directedspeech

–  NorthWindandSunfable

•  Na&vespeakersofAmericanEnglishandBengali(n=10each)–  Neitherhastone,orlexicalpitchaccent–  Bothhaveintona&on

•  AllrecordingsinsoundboothwithaShureSM10Ahead-mountedmicrophonepluggedintoalaptopcomputerviaapreamplifier

•  2condi&ons(IDS,ADS)x3repe&&ons=6recordingsperspeaker–  2EnglishtranscriberstrainedonADS–  1Bengalitranscriber

•  Defaultreading(non-IDS):“Readatacomfortablepace.”

•  Simulatedinfant-directedreading(IDS):“Readasifspeakingtoyour4-mo-oldchild.”

7

Twostyles

F0Rangef01 f02 f03 f04 f05

m01 m02 m03 m04 m05

100

200

300

400

100

200

300

400

non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDSstyle

Fund

amen

tal f

requ

ency

(Hz)

stylenon−IDSIDS

BengaliThemiddleline=meanF0averagedacrossIPsforagivenspeaker;boHom&topbounds=theminimum&maximumF0averagedacrossIPs.

IPsf01 f02 f03 f04 f05

m01 m02 m03 m04 m05

0

50

100

0

50

100

non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDSStyle

Number

of into

nation

al phra

ses

f01 f02 f03 f04 f05

m01 m02 m03 m04 m050

20

40

60

80

0

20

40

60

80

non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDSStyle

Number

of into

nation

al phra

ses

Bengali

English

BENGALI

B-ToBI:(Khan,2008;Khan,2014)

IP

APHaPAL*

L*

APLaPAH*

H*

Ha

La

ip

L-

H-LH-HL-

L%

H%

LH%HL%

HLH%

GrammaroflicitsequencesoftonalelementsproposedintheB-ToBImodelofBengaliintona&on,ignoringthef-markedtonesassociatedwithfocusaswellastheeffectsofconcurrentboundarytoneoverriding.Sequencescanonlybeginatstateswithathicklyoutlinedcircle(“APHa”and“APLa”)andterminateatstateswithadoubleoutlined

circle(“IP”).

Nostacking;onlyoverridesatipandIPboundaries

PitchAccents f01 f02 f03 f04 f05

m01 m02 m03 m04 m05

0

50

100

150

200

0

50

100

150

200

non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDSStyle

Frequency

Pitch accent L* H* L*+H * L*+fH fH*

Bengalipitchaccents

fH*

thatmuchtravelertheirshawlheld&ghtly(IDS)

thatmuchtravelerhis/hershawlheld&ghtly(non-IDS)

L*

13

BoundaryTones f01 f02 f03 f04 f05

m01 m02 m03 m04 m05

0

50

100

0

50

100

non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDSStyle

Frequency

Intonational phrase ambig L% LH% HLH% H% HL% M%

L% LH% HLH%

H% HL%

0.0

0.1

0.2

0.3

0.4

0.0

0.1

0.2

0.3

0.00

0.05

0.10

0.15

0.000

0.025

0.050

0.075

0.100

0.125

0.00

0.02

0.04

0.06

non−IDS IDS non−IDS IDS non−IDS IDS

non−IDS IDS non−IDS IDSStyle

Mea

n re

lativ

e fre

quen

cy

Intonational phrase L% LH% HLH% H% HL%

BengaliIPs

LH% H% L%

L%

] ] ]

]Atthatmomentatravelerwearingaheavyshawlcamewalkingtowardsthem

Atthatmomentatravelerwearingaheavyshawlcamewalkingtowardsthem

16

Bengaliboundarytones

Hainnon-IDSDefault

HLH%inIDSCon,nua,on

HL%inIDSTopicaliza,on

17

ENGLISH

MAE-ToBI:(Ladd,1996;Pierrehumbert,1980;Pierrehumbert&Hirschberg,1990)

IP

0 1%H

PA

H*

L*

L* + H

L + H*

H + !H*

ip

H-

!H-

L-

H%

L%

GrammaroflicitsequencesoftonalelementsproposedintheMAE_ToBImodelofAmericanEnglishintona&on.Sequencescanonlybeginatstateswithathicklyoutlinedcircle(“0”,“1”)andterminateatstates

withadoubleoutlinedcircle(“IP”).

StackingobservedatipandIPboundaries

ComparisonofBengaliandEnglish

•  BengalinotEnglishhasaregularrepea&ngpaHern– DuetorestrictedPAandAPboundaryinventory

•  BothlanguagemarkfocuswithPAchoiceandpost-focalde-accen&ng

•  Bengalihas3–AP,ip,IP(comparedto2-ipandIPinEnglish)tonally-markedprosodicstructures– MorecomplexboundarytonesinvolvingpitchchangesforipandevenmoreforIP

PitchAccents

f01 f02 f03 f04 f05

m01 m02 m03 m04 m050

50

100

150

200

0

50

100

150

200

non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDS non−IDS IDSStyle

Raw

freq

uenc

y

Pitch accent * H* H+!H* L* L*+H L+H*

Frequency of tones conditioned on speaker and style, T1

English:IPs

L-H% L-L% L-L%

L-L%

] ] ]

]AndsotheNWwasobligedtoconfessthattheSunwasthestrongerofthetwo

AndsotheNWwasobligedtoconfessthattheSunwasthestrongerofthetwo

L-L%

] 22

Comparingintona&onalgrammarsinADSandIDS

•  Constructafinitestategrammarforintona&onaltonotac&cs,commonacrossADS/IDS

•  Es&mateweightsovertransi&onsinfinitestateacceptorusingproduc&oncorpusfrequencies

•  CompareweightsbetweenADSandIDS

DefiningafinitestateacceptorforBengaliintona&on

•  Usexfst(BeesleyandKarHunen2003):define“extended”regulargrammarswithhigh-levellanguage(regularexpressions)

•  Exampledefini&on:–  define ipSequence [ [ APSequence ]* ipEdge ];–  “AniptonesequenceconsistsofzeroormoreAPtonesequences

followedbyan“ipEdge”(PA+iptone).”

•  Constructdeterminis&cfinitestateacceptor– Determinis,c:giveninputandcurrentstate,thereisonlyonepossibleoutgoingpathfromthecurrentstate

0

1

[ 3L

4f

2H

6*

H

5

*

8+

9

]

H

11f

12[

7]

15

H

16

L

17f

H

18L

20

a -

19

%

-

%

21

H

22H

-

%

23

H

]

24]

a

10[ - %

13

H

14L

L

-

%

a -

%H

%DETERMINISTICFSAforBENGALI

0

1

[ 3L

4f

2H

6*

H

5

*

8+

9

]

H

11f

12[

7]

15

H

16

L

17f

H

18L

20

a -

19

%

-

%

21

H

22H

-

%

23

H

]

24]

a

10[ - %

13

H

14L

L

-

%

a -

%H

%

Weightsforpitchaccent,APtonepartofFSMverysimilar

0

1

[ 3L

4f

2H

6*

H

5

*

8+

9

]

H

11f

12[

7]

15

H

16

L

17f

H

18L

20

a -

19

%

-

%

21

H

22H

-

%

23

H

]

24]

a

10[ - %

13

H

14L

L

-

%

a -

%H

%

DifferencescomeinweightsforIP/iptones

PaHernsinarcweightdifferences

•  Atchoicepointforipvs.IPtone,IDSgoeswithanIPtonemorefrequently

•  AtachoicepointforanIPtonetoincludemoretonaltargetsornot,e.g.L%vs.LH%,HL%vs.HLH%,IDSgoeswithmoretonaltargetsmorefrequently