THEMEDIUM-TERMDYNAMICSOFACCENTSONREALITYTELEVISION MorganSonderegger MaxBane PeterGraff McGillUniversityand UniversityofChicago UniversityofVienna CentreforResearchon Brain,Language,andMusic Howflexibleisanindividual’saccentduringadulthood,andhowdoesthisflexibilityrelateto longer-termchange?Previousworkhasfoundthataccentsareremarkablyflexibleinconversa- tionalinteraction,butpredominantlystableoveryears,leadingtoverydifferentviewsoftherole medium-term ofindividualsincommunity-levelsoundchange.Thisarticleexamines accentdy- namics(daystomonths)bytakingadvantageofa‘naturalexperiment’:arealitytelevisionshow wherecontestantsliveinanisolatedhouseforthreemonthsandareconstantlyrecorded,forming aclosedsystemwhereitispossibletobothdeterminethedynamicsofcontestants’speechfrom daytodayandreasonaboutthesourcesofanyobservedchanges.Webuildstatisticalmodelsto examinetimedependenceinfivephoneticvariableswithinindividuals,in14.5hoursofsponta- neousspeechfromtwelveEnglish-speakingcontestants.Wefindthattimedependenceinpronun- ciationisubiquitousoverthemediumterm:largedailyfluctuationsinpronunciationarethenorm, whilelonger-termchangeoverweekstomonthsoccursinaminorityofcases.Thesepatternsmir- rortheconflictingfindingsofpreviousworkandsuggestapossiblebridgebetweenthetwo.We arguethattimedependenceinphoneticvariablesisinfluencedbycontrastbetweensounds,aswell assystematicdifferencesbetweenspeakersinhowmalleabletheiraccentsareovertime;however, wefindonlylimitedevidenceforconvergenceinindividuals’accents.Ourresultshaveimplica- tionsfortheoriesoftheroleofindividualsinsoundchange,andsuggestthatmedium-termpro- nunciationdynamicsareafruitfuldirectionforfuturework.* Keywords:longitudinalstudies,accentdynamics,phoneticvariation,individualdifferences,lan- guagechange Introduction. 1. Two of the most striking aspects of language are stability and change.Bothaspectsareespeciallyclearforhowsoundsarepronounced,thefocusof thisarticle.Atthelevelofindividuals,weintuitivelyknowthataspeaker’saccentcan shiftasafunctionofherinterlocutor,andthatsomepeople’saccentsseemtoshiftper- accentchange manently( ),forexample,aftermovingtoanewdialectregion.How- ever, we also intuitively know that many people’s accents are stable over time: this defaultassumptionunderliesourabilitytoidentifywheresomeoneisfrombytheirac- cent.Atthelevelofspeechcommunities,manyaspectsofthephoneticandphonologi- sound change cal system are stable at a given point in time, yet cases of are always occurring(e.g.Labov1994).Thisarticleaddressesthreebroadquestionsaboutaccent dynamicsandsoundchange:howplasticaretheaccentsofindividualspeakersduring adulthood,whatarethesourcesofthedynamicsofaspeaker’saccent,andwhatisthe relationshipofaccentplasticityinindividualstocommunity-levelsoundchange? *We thank Molly Babel,Lauren Hall-Lew,Tyler Kendall,Jane Stuart-Smith,NatashaWarner,and an anonymousrefereeforhelpfulcommentsondraftsofthisarticle,andthemanyotherpeoplewhohavepro- videdusefulfeedbackonthisproject,includingPeterAuer,RinaFoygelBarber,PaulBrazeau,AlexFine, JamesKirby,MattGoldrick,JohnGoldsmith,DanJurafsky,RobinQueen,JasonRiggle,TylerSchnoebelen, CharlotteVaughn,andAlanYu;aswellasaudiencesatCLS2010,LSA2011,CUNY2011,NWAV2012, LabPhon2014,ICPhS2015,andatUSC,IndianaU.,U.Michigan,McGill,U.Edinburgh,U.Ottawa,U. Minnesota,U.Toronto,Cornell,NorthwesternU.,andMIT.WethankN.Rothfels,M.Nelson,T.Knowles, M.Schwarz,M.Labelle,L.Bassford,R.Hwang,H.Hsieh,andM.Coumelforresearchassistance.Wegrate- fullyacknowledgepermissionfromChannel4/EndemoltoaccessfootagefromBigBrother9UK.Prelimi- naryversionsoftheVOTresultsweregiveninBaneetal.2010andSonderegger2015,andinSonderegger 2012forallvariables.ThisworkwassupportedbygrantsfromtheSocialSciencesandResearchCouncilof Canada(#430-2014-00018)andtheFondsdeRechercheduQuébecSociétéetCulture(#183356). 598 PrintedwiththepermissionofMorganSonderegger,MaxBane,&PeterGraff.©2017. Themedium-termdynamicsofaccentsonrealitytelevision 599 short-term Previousworkhasaddressedthesequestionsontwotimescales: shifts inpronunciationduringconversationandlaboratoryexperiments(seconds–hours),and long-term accentchangeoverthelifespan(years). Short-term. 1.1. Onelong-standingbodyofworkemphasizestheflexibilityofthe sound systems of individuals, which are constantly updated over time as a result of interaction(Hockett1965,Paul1880;seeGarrett&Johnson2013).Forexample,con- emergentist temporary theories of phonetics and phonology (e.g. Johnson 1997, Pierrehumbert2001),whosecoretenetsgobacktotheNeogrammarians,assumethata speaker’scognitiverepresentationofsoundsincludesallexampleseverheard.Thisrep- resentationisupdatedwitheachnewinteractionandusedinspeechproduction.Thus, emergentist models predict that pronunciation norms can and will shift over time, in- cludingduringadulthood,asaresultofinteractions. Aprimary source of evidence for accent plasticity in adults comes from short-term shiftsinhowonespeaks(overseconds–hours),inconversationsandinlaboratoryset- tings,underexposuretootherpeople’sspeech.Theseshifts(termedimitation,(phonetic) convergence,accommodation,etc.)havebeendocumentedusingavarietyofparadigms (Pardo2013).Asassessedbyperceptualmeasures,subjectsshifttheiroverallpronunci- ations toward a target voice in word-shadowing tasks (Fowler et al. 2003, Goldinger 1998)andtowardtheirinterlocutorinconversationalinteraction(e.g.Pardo2006).Spe- cificacousticvariablestypicallyalsoundergoshort-termshiftsinbothinteractiveand noninteractivesettings.Forexample,AmericanEnglishspeakersincreasedtheVOTof word-initial voiceless stops toward a model talker in an imitation task (Nielsen 2011) andshiftedtheirproductionsoffivevowels(inF1/F2space)towardamodeltalkerina shadowingtask(Babel2011).Pardo(2009)alsofoundthatAmericanEnglishspeakers shiftedvowelformantsinconversationalinteraction,butinmorecomplexways.Inthese andotherstudiesofshiftsinphoneticvariables,theexistenceofsomeshift,asaresultof exposuretoanotherperson’sspeech,isquiterobustacrossspeakers. Short-termshiftsinpronunciationaretosomeextent‘automatic’consequencesofin- teraction(Delvaux&Soquet2007,Goldinger1998).Theyarealsoheavilymodulated bythreetypesoffactors,whichresultinthesignificantvariabilitybetweenspeakersin thesizeanddirectionalityofshiftsobservedinmostshort-termstudies: Socialfactors ii(i) ,suchasattitudetowardtheinterlocutorandgender(Babel Communication accom- 2010, Bourhis & Giles 1977, Namy et al. 2002). modationtheory (Gilesetal.1991,etseq.)proposesthattheseshiftsresult accommodation from individuals managing social distance using an strat- convergence divergence egy,suchas or (e.g.toexpresssolidarityordis- approval). Linguistic factors i(ii) . For example, Nielsen (2011) cites contrast mainte- nancetoexplainwhyEnglishspeakerswillshiftVOTofvoicelessstopsto- wardlengthenedbutnotshortenedVOT(cf.Babel2011,Mitterer&Ernestus 2008). Individual differences (iii) , correlated with factors such as personality traits andgender(Namyetal.2002,Yuetal.2013). Insum,plasticityinpronunciation,modulatedbymultiplefactors,isthenormover styleshifting: seconds–hoursforadults.Thisplasticityisinlinewiththeubiquityof shiftsinaspeaker’slinguisticusageasafunctionoftheaddressee,topic,andsoforth (e.g. Bell 1984, Eckert 2000, Rickford & McNair-Knox 1994), possibly many times overthecourseofaday(e.g.Coupland1980,Hindle1980). 600 LANGUAGE,VOLUME93,NUMBER3(2017) Changebyaccommodation .Theexistenceofsubstantialaccentplasticityininter- actionsgoesnaturallywiththeviewthatchangeduringadulthoodisanimportantdriver ofsoundchangeincommunities.VersionsofthisviewgobacktotheNeogrammarians changeby (Paul1880),assummarizedbyAuerandHinskens(2005),whocallitthe accommodation model (CBA) .TheCBAmodelexplainstherelationshipbetweenin- dividual-levelandcommunity-levelchangeasasequenceofthreesteps:(1)peopleac- commodatetoeachotherduringinteractions;(2)eventually,agivenindividual’snorms changeastheresultofaccumulationoftheseinteractions;(3)theinnovationspreadsin the wider community (as individuals undergo step 2). Different versions of the CBA modeladdressdialectchange/contactsettingsalone,orallsoundchange(e.g.Bloom- field 1933, Garrett & Johnson 2013, Labov 1990, Trudgill 1986, 2004), and differ in whether short-term shifts (and thus steps 2–3) are fundamentally automatic (every in- teractionmakesthesoundsystemofinterlocutorsmoresimilar)orfundamentallysocial (as proposed by communication accommodation theory). Regardless of their mecha- nism, short-term shifts are generally assumed to be ‘the driving force of language change’(Auer&Hinskens2005:356).Thefactthatmostshort-termliteratureconsiders adultssuggeststhatsteps1–2referbydefaulttoadults.Thus,thelinkbeingmadebe- tween accent plasticity in adulthood and the nature of sound change is this: because long-termchange adults’pronunciationsaresoplasticininteractions(step1), during soundchange adulthood(step2)playsanimportantroleincommunity-level (step3). Long-term. 1.2. Onatimescaleofyears,thetraditionalviewisthatanindividual’s linguisticsystemislargelyfixedinadulthood(e.g.Chambers2003:197).Theassump- apparent-time tionofaccentstabilityoveryearsunderliesthewidespreaduseofthe construct tostudysoundchangeinprogressusingasynchronicsample(Cukor-Avila &Bailey2013). Previous work has examined the extent of postadolescent accent plasticity in two kindsofsettingswhereaccentchangetowardchangingcommunitynormsseemsintu- itively likely: individuals who remain in the same speech community, where some panelstudies changeisinprogress( ;Sankoff2005,2013),andindividualswhohave dialect change studies moved between dialect regions ( ; Auer et al. 2005, Siegel 2010).1 For example, Sankoff and Blondeau (2007) examine change in rhotic realiza- tion([r]→[ ],acommunity-levelsoundchangeinprogress)inMontrealFrenchusing ʀ apanelofthirty-twospeakers,recordedelevenyearsapart,andfindrelativestabilityin mostindividuals(72%),withtheremainderincreasingtheir[ ]use.Whilemostlarge- ʀ scaledialectchangestudiesdonotbreakdownresultsbyindividualspeakers,thosethat do suggest that significant accent change in adulthood is uncommon. For example, Foreman (2003) examines six American speakers who settled in Australia for whom longitudinal data is available over ten to twenty-seven years; five of the six speakers show little or no significant change across six phonological variables. However, case studieshavehighlightedthefactthatdramaticaccentchangeispossible.Forexample, QueenElizabethII’srealizationofEnglishvowelshaschangedsignificantlyoverfifty yearsofradioaddresses,oftenparallelingcommunity-levelchanges(Harringtonetal. 2000, et seq.); andYiddish folk singer Sarah Gorby shows a mixture of stability and changeacrossphonologicalvariablesoverfiftyyears,withchangegenerallytowardthe standard(awayfromhernativedialect)(Prince1987).Moregenerally,long-termstud- iesfindthatbothvariablesandspeakers(foragivenvariable)differsubstantiallyinthe degreeofplasticityoveryears(Siegel2010:51),foravarietyofreasons.Thoughfurther 1Wedonotconsideragegrading,whereavariable’susechangesduringadulthoodinapredictableway. Themedium-termdynamicsofaccentsonrealitytelevision 601 workisneededgiventhisheterogeneity,thepicturethatemergestodatefromlong-term studies across a range of languages and variables (e.g. Bowie 2005, Brink & Lund 1975,Nahkola&Saanilahti2004,Sancier&Fowler1997,Stanford2008)isthat‘the defaultforadultsisapparentlystability’,whileaminorityshowsignificantpronuncia- tionchange,usuallyinthedirectionofcommunity-levelchangesinprogressorambient norms(Sankoff2013:274). Generationalchange .Thefindingthatadultsshowlimitedandheterogeneouslong- termplasticityinpronunciationgoesnaturallywiththeviewthatchangeduringadulthood isnotaprimarydriverofcommunity-levelsoundchange.Aninfluentialproponentof thisviewisLabov(1994,2007),whoarguesthatpronunciationchangesinternaltospeech generationalchange transmis- communitiesoccurprimarilyvia :intergenerational sion incrementation ofnormsfromadultstochildren,and bychildreninthedirection ofchangesinprogressduringchildhoodandadolescence.Bycontrast,thetypicalmech- anismofchangesrootedindialectcontactisdiffusioninthecourseofinteractionbetween adultswhousedifferentpronunciations.Diffusionislessimportantthantransmissionas asourceoflinguisticdiversitybecauseitisdrivenbyadults,whoshowlessandmorespo- radic‘capacitytochangetheirlinguisticsystems’comparedtochildrenandadolescents (Labov2007:349).WhileLabov’saccounthasbeensubjecttodebate(e.g.Babeletal. 2013),itrepresentsacommonview:changeinadulthoodisnotanimportantfactorinthe majorsourceofsoundchange(internalchange),whileexternalchangeisalessimportant sourcepreciselybecausechangeinadulthoodislimitedandsporadic. Mediumterm 1.3. .Empiricalevidencefromtheshort-termandlong-termliteratures broadlysuggeststhataccentsarebothplasticduringinteractionsandlargelystableover thelifespan,andassociatedtheoreticalviewpointsreachconflictingconclusionsaboutac- centplasticityinindividualsanditsrelationshiptocommunity-levelsoundchange.This conflictcomesfromextrapolatingfromshort-termandlong-termresultstoaccentplas- mediumterm ticityinindividualsoverthe (days–months),aboutwhichlittleisknown. Long-termstudiessuggestthataccentstabilityisthenorminadulthoodoveryears, butlittleisknownaboutaccentdynamicsinadultsonshortertimescales(cf.Barden& Großkopf 1998, Evans & Iverson 2007, Pardo et al. 2012, where sampling points are separatedbymonths).Areasonablenullhypothesisformedium-termdynamicswould sta- bethatanindividual’sspeechdoesnotchangeoverdays–months;wecallthisthe tionarityhypothesis .Wecandistinguishtwoversionsofthestationarityhypothesis, thinking about the trajectory of an individual’s ‘baseline’ use of a phonetic variable everyday,overaperiodofmonths(schematizedinFigure1),aftercontrollingforother factors(style,linguisticcontext,etc.).Inthestrongversion,therecouldbenotimede- pendenceatall(typeA),eitherfromdaytodayoroverlongerperiods.Aweakerver- by-dayvariability sionwouldbethatindividualsvaryfromdaytoday( ),butnotover longerperiods(typeC).Thereisalmostnoworkexaminingwhetheranindividual’sac- centfluctuatesfromdaytoday(cf.Heald2012,Pisoni1980,discussedbelow),though NahkolaandSaanilahti(2004)suggestthispossibility.2 Short-termstudiesshowthatspeakersregularlyadjusttheirpronunciationduetothe speechofothers.Theproposedlinkbetweenshort-termshiftsininteractionandlonger- term change is at the heart of the CBAmodel and motivates many short-term studies (e.g. Babel 2011, Delvaux & Soquet 2007, Nielsen 2011, Pardo 2006).An important persistencehy- initialassumptionbeingmadeintheseliteratures,whichwecallthe 2Incontrast,Cukor-Avila(2015)andRickfordandPrice(2013)haveexamineddailyfluctuationsinindi- morphosyntactic viduals’useof variables,focusingoneffectsofstyleshiftingandmethodology. 602 LANGUAGE,VOLUME93,NUMBER3(2017) Figure 1.Schematicofpossibletypesoftimedependenceinaphoneticvariablewithinindividualspeakers: nochange(A),timetrend(B),by-dayvariability(C),by-dayvariabilityandtimetrend(D).Solidline indicatesthevariable’svalueoneachday;dashedlinesindicateitsmeanvalueoverseveraldays. pothesis ,isthatshort-termshiftspersistbeyondindividualinteractions;theymaythen accumulateandeventuallyleadtochangeinanindividual’spronunciationnormsover themediumterm.Toourknowledge,however,thereisnoworkexaminingthepersis- tence of short-term shifts in use of a phonetic or phonological variable for more than onehour.3Thepersistencehypothesispredictsthatifanindividualengagesinthesame type of interactions sufficiently often, there should be steady change in his ‘baseline’ use of a phonetic variable over days–months—beyond any by-day variability—which time trend we term a .Aphonetic variable could show a time trend without by-day variability(Fig.1:typeB),orbothatimetrendandby-dayvariability(Fig.1:typeD). By-dayvariabilityandtimetrendsformtwoindependentdimensionsofmedium-term timedependence:anindividuals’pronunciationcouldshoweither,both,orneither. Medium-termaccentdynamicsinaclosedsystem 1.4. .Thedisconnectbetween short-termandlong-termplasticityandthepaucityofempiricaldataontimescalesinbe- medium-term tweenmotivatesthecurrentstudy,whichinvestigates timedependencein speechproductioninindividualsbytakingadvantageofa‘naturalexperiment’:thereal- itytelevisionshowBigBrotherUK,whosestructureisuniquelysuitedtoinvestigating howandwhyanindividual’saccentchangesoverthemediumterm.Theshowcontains speechfromthesameindividuals,recordedonanear-dailybasisoverthreemonths,mak- ingitpossibletoexaminewhetheraspectsofcontestants’speechshowby-dayvariabil- ity,timetrends,orboth.Contestantsinteractwitheachotherconstantly,withoutaccess totheoutsideworld;thehouseisthusalinguistically‘closedsystem’(Baneetal.2010), asmallcommunitywherepersistenceofshort-termshiftsinpronunciationmightbeex- pectedtobeespeciallylikely,andwhereitisinprinciplepossibletotestwhetherchange inanindividual’sspeechcanberelatedtosocialinteraction. We first describe a corpus of spontaneous English speech from one season of this show, in which we examine five phonetic variables for twelve contestants over up to threemonths(§§2–3).Foreachvariable,webuildstatisticalmodelstocharacterizeits timedependencewithineachspeaker,aftercontrollingforotherfactors(§4).Wethen usetheresultsofthesemodelstoaddresstworesearchquestionsaboutaccentdynamics overthemediumterm. First, what qualitative kinds of time dependence do phonetic variables show within individualspeakersoverthreemonths(§5)?Weconsiderthetypesoftimedependence showninFig.1,andwefindthatmedium-termtimedependenceofonekindoranother isubiquitousacrossspeakersandvariables,andthattimedependenceisdueprimarily toby-dayvariabilityandsecondarilytotimetrends.Second,towhatextentcanweac- 3Goldinger(2000)showspersistenceoveroneweekofanoverallpercept,butacousticvariablesarenot examined. Themedium-termdynamicsofaccentsonrealitytelevision 603 count for the observed patterns of variability over time (§6)? We consider the same typesofpotentialsourcesthatmediateshort-termpronunciationshifts—socialfactors, linguisticfactors,andindividualdifferences—andfindsomeevidenceforaroleofeach inshapingmedium-termaccentdynamics. Thesefindingsallowus(§7)toevaluatethestationarityandpersistencehypotheses, to situate medium-term dynamics between the disparate patterns individuals show on short-termandlong-termtimescales,andtoevaluatethemechanismofaccentdynam- icsinindividualsandthepossiblerelationshiptocommunity-levelchange. Thebigbrothercorpus 2. . Show description 2.1. .The Big Brother corpus consists of speech from the ninth seasonoftherealitytelevisionshowBigBrotherUK(Channel4/Endemol),whichaired from June 5 to September 5, 2008 (ninety-three days).4 Twenty-one contestants (or housemates ) took part in the show: sixteen entered the Big Brother house on day 1, andfivemoreenteredlaterintheseason.Housematesweregraduallyevictedduringthe seasonbyacombinationofnominationbyotherhousematesandvotingbytheviewing public.Thelasthousemateremainingwonacashprize. While on the show, housemates had essentially no linguistic input from the outside world:theydidnotleavethehouse,interactwithpeoplenotinvolvedwiththeshow,or (withrareexceptions)haveaccesstomedia.Theyspentmostoftheirtimeinteracting witheachotherinsomeform,forexample,inunstructuredconversationsorwhilepar- diary ticipating in tasks set by Big Brother. The one important exception was the room , an isolated room where housemates could go to speak with ‘Big Brother’. Big Brotherwasinfactdifferentpeople(maleandfemale)atdifferenttimes;he/shecould seehousemates,butcouldnotbeseenbythem,andcommunicatedonlythroughaudio. Housemateswenttothediaryroomtotalkabouttheirfeelings,eventsinthehouse,and soforth,andcouldeithergotothediaryroomvoluntarilyorbecalledbyBigBrother. Housemateswererecordedatalmostalltimes,includingbywearablemicrophones. Duringtheseason,thepubliccouldseevideoofhousematesviaalivefeedorvariouspro- ducedshows,includingdaily‘Highlights’showsandweekly‘Diaryroomuncut’shows, whichconsistedofcontinuoussegmentsfromthehouse,presentedwithoutcommentary. Table 1 gives basic demographic information for the twenty-one housemates, who come from diverse dialect regions. Sixteen housemates are native speakers of British dialects. Five housemates reside in the UK but are not native speakers of British di- alects. Sara and Darnell are native English speakers fromAustralia and the USA, re- spectively;SylviaandMohamedwereborninSierraLeoneandSomalia,respectively, and speak near-native English with light accents. Kathreya is a native Thai speaker whoseEnglishisheavilyaccentedandfrequentlyungrammatical. Corpusdescription. 2.2. Thecorpusconsistsofallsegmentsfromthe‘Highlights’ and‘Diaryroomuncut’showswhereasinglehousematewasinthediaryroom,which diary room clips clips we call (or ).Audio from all clips was broadcast quality.The 749 clips contain roughly 14.5 hours of housemate speech. The corpus is unbalanced across housemates (Table 1), because housemates were on the show for different amountsoftime:thelesstimeahousematespentinthehouse,thelessfrequentlytheir speechwassampled(clipsoccuronceper0.8–5.4days,fordifferentspeakers).Thus,to addressourresearchquestionsabouttimedependenceinindividualhousemates’useof 4 Information about the show and housemates comes fromWikipedia (2012a,b).This corpus is an ex- pandedversion(roughlytwiceaslarge)ofthatusedinSonderegger2012. 604 LANGUAGE,VOLUME93,NUMBER3(2017) speaker gender age dialectregion dayson #ofclips housemate show speech Dale M 21 N.England 65 43 0:43 Darnell M 26 USA 93 73 1:24 Kathreya F 31 L2Thai 90 56 1:08 Lisa F 40 N.England 86 53 1:02 Luke M 21 N.England 58 49 1:09 Michael M 34 S.Scotland 93 81 1:42 Mohamed M 25 London 90 51 0:53 Rachel F 24 S.Wales 93 69 1:03 Rebecca F 21 W.Midlands 51 34 0:32 Rex M 24 London 93 71 1:25 Sara F 27 Australia 64 39 0:44 Stuart M 25 N.England 57 32 0:38 Alexandra F 23 London 14 17 0:25 Belinda F 44 S.England 15 7 0:08 Dennis M 24 S.Scotland 23 7 0:09 Jennifer F 22 N.England 30 13 0:20 Mario M 43 N.England 37 15 0:19 Maysoon F 29 London 27 5 0:03 Nicole F 19 S.England 22 19 0:24 Stephanie F 19 N.England 9 9 0:08 Sylvia F 22 London 23 6 0:09 total 749 14:28 Table 1.Demographicinformation,lengthofstayintheBigBrotherhouse,andamountofdataintheBig Brothercorpusforeachofthetwenty-onehousematesfromBigBrother9UK.Thehorizontalline separatesthetwelve‘corehousemates’(top)andtheotherhousemates. each phonetic variable—in particular, distinguishing between by-day variability and time trends—we can only consider housemates who spend a relatively long period in thehouse.Fiftydays(ofninety-three)waschosenasanarbitrarycutoff,leavingtwelve core housemates housemates (of twenty-one), who we refer to as the (seeTable 1). The core housemates account for 85.6% of speech in the corpus and are the focus of mostanalysesbelow. The corpus is limited to diary room clips of single housemates in order to best ad- dress our research questions, given that it was not feasible to transcribe more than a fractionoftheproducedepisodes(>100hours).Limitingthecorpustoonetypeofin- teractioninarelativelyconstantsettingallowsustominimizedifferencesinspeaking stylebetweendifferentdays(i.e.clips)andthusbetterassessthestationarityhypothe- sis.5TheonlyinteractionintheclipsiswithBigBrother,whoseroleisusuallylimited tobriefquestionsoranswers.Theregisterofthespeechisgenerallycasualandconver- sational, with characteristics of a sociolinguistic interview, but with the clear self- awareness and performativity expected given that the interaction may eventually be televised.Thecorpusallowsustoexaminehoweachhousemate’s‘baseline’linguistic usagevariesovertime,abstractingawayfromshort-termshiftsthatmayoccurduring conversationwithotherhousemates. Eachclipwassegmentedintospeakerturnsandorthographicallytranscribedbyre- searchassistantsandthefirstauthor.Theorthographictranscriptionandaudioofeach clip were then force-aligned using a version of the HTK-based aligner from FAVE (Rosenfelderetal.2011,Youngetal.2006),customizedfortheBigBrotherCorpus. 5Notethatitwasnotpossibletoassesstimeofday(e.g.morningvs.evening)giveninformationinthecor- pus;see§7.1fordiscussion. Themedium-termdynamicsofaccentsonrealitytelevision 605 Data. 3. Weexaminethedynamicsoffiveaspectsofpronunciationforspeakersin phonetic variables the Big Brother house ( ): voice onset time (VOT), coronal stop goose strut trap deletion(CSD)rate,andthequalityofthreevowels( , ,and ,usingthe ‘lexicalset’notationofWells1982foravowel’srealizationinagivendialect). These variables provide complementary evidence for our research questions about theexistenceandsourcesofmedium-termtimedependenceinpronunciation.First,all variables differ greatly across varieties of English, meaning the possibility exists for contestants’ pronunciations to influence each other. VOT has been found to be very flexibleovershort-termtimescales(e.g.Nielsen2011,Sancier&Fowler1997),making it a logical place to look for medium-term plasticity. Examining CSD lets us study whethermedium-termtimechangeobtainsformorecategoricalaspectsofpronuncia- tion, as well as continuous phonetic parameters. The three vowels examined differ along two dimensions thatare possible sources of medium-termtimedependenceand mightaffectthelikelihoodofconvergencebetweenhousemates.Previousworkhasar- goose strut trap social gued that, compared to , the realizations of and have high salience acrosstheUK,whichhasbeenarguedtoconstrainwhichvariablescanshift overtheshortandlongterm(e.g.Babel2010,Trudgill1986)andmightaffectavari- Goose soundchange able’smedium-termplasticityaswell. isundergoing incommu- nities across the UK (e.g. Docherty 2010, Haddican et al. 2013, Hawkins & Midgley strut trap 2005),while and arerelativelystable.Speakersmightshowmoreflexibil- ityintherealizationofavowelundergoingsoundchange,iftheirexposuretoagreater numberofvariants(outsidethehouse)givesthemabroaderrangeof‘self-exemplars’ todrawoninconvergingtowardotherspeakers. Wefirstintroduceeachphoneticvariable,thendescribeannotationanddata-cleaning steps,andsummarizetheresultingdataset. Voice onset time 3.1. . VOT, the time difference between the onset of a stop’s re- lease burst and the onset of voicing in a following segment, is an important phonetic cueforthecontrastbetweenEnglish‘voiced’and‘voiceless’stops(e.g.Docherty1992, Lisker&Abramson1967).VOTmaybepositive(burst+aspirationduration)ornega- tive (duration of voicing preceding burst). (Phonologically) voiceless stops are pro- duced with variable degrees of positiveVOT, while (phonologically) voiced stops are produced with either shorter positive VOT or negative VOT. Variability in VOT has beenstudiedmostlyinlabspeech(seeAuzouetal.2000,Docherty1992),butsomere- centworkexaminesspontaneousEnglishspeech(Chodroffetal.2015,Yao2009),in- cluding Stuart-Smith and colleagues’ (2015) study of variability in positive VOT in spontaneousGlasgowvernacular—whoseanalyticalchoicesweoftenfollow,andwho discuss the issues involved in measuring VOT in spontaneous speech. Like Stuart- Smithandcolleagues,wemeasuredpositiveVOT(summedburstandaspirationdura- word-initial tion) for every stop token produced with a burst or aspiration, without taking account of negative VOT or voicing during the closure. Thus, ‘voiced stops’ phonemically throughoutthisarticlealwaysmeans voicedstops,asopposedtostops producedwithnegativeVOT. Annotation and data set . We measured VOT semi-automatically for all word- initialstopsinthecorpus(n=16,784voiced,13,777voiceless),usingaproceduresim- ilartothatofStuart-Smithetal.2015. automaticmeasurement First,an ofVOTforeachtokenwasobtainedbyapply- ingAutoVOT(Keshet et al. 2014, Sonderegger & Keshet 2012).AutoVOTrequires a classifierthathasbeentrainedonmanuallylabeledVOTdata,aswellasawindowof 606 LANGUAGE,VOLUME93,NUMBER3(2017) timeintheaudiofileforeachtoken(specifiedinaPraatTextGrid;Boersma&Weenink 2011)inwhichtosearchforthebeginningoftheVOTinterval.Applyingtheclassifier toeachtokeninafileyieldspredictedVOTintervals,whichareoutputtedonanewtier oftheTextGrid.TopredictVOTforvoicelessandvoicedstops,weusedtheclassifiers forvoicelessandvoicedEnglishstopsdistributedwithAutoVOT.Thewindowforeach token was taken to begin and end 25 ms before and after the force-aligned segment boundaries.Theparametersforminimum/maximumpredictedVOTweresetto15/250 msforthevoicelessclassifierandto5/150msforthevoicedclassifier,andotheralgo- rithmparameterswerekeptatdefaultvalues. manualcorrection Second,inthe phase,twoorthreephoneticallytrainedannota- tors(twoforvoiced,threeforvoicelessstops)reviewedthepredictedVOTintervalsin Praat.Foreachinterval,theannotator:(a)checkedwhethernoburstwaspresent(e.g. stopisrealizedasafricative),inwhichcasethetokenwasmarkedforexclusion;(b)de- terminedwhethertheVOTintervalboundarieswerewhereshewouldhaveplacedthem ifannotatingVOTmanually;and(c)manuallycorrectedtheboundaries,ifthiswasnot thecase.Step(a)resultedin3,474excludedtokens.Manualannotation(stepsb–c)was performed in Praat.The left boundary was placed wherever the first ‘large’amplitude increaseinhigh-frequencyfricationoccurred,establishedusingtheamplitudetrackand spectrogram; if there was a gradual rise in frication, the boundary was placed at the midpoint.Whenmultipleclearlyseparateburstsoccurred,thelastonewasusedasthe leftboundary.Therightboundarywasdeterminedprimarilyusingthewaveform:ifpe- riodicitywasnotpresentbeforetheburst,atthezerocrossingclosesttotheonsetofpe- riodicity;ifperiodicitywaspresentthroughouttheburst,atthepointwhereamplitude begantoriseandgeneralwaveformshapechangedabruptly. Anumberoffurtherexclusionsweremade.All1,511tokensfromKathreyawereex- cluded, since her data may show extensive transfer fromThai (which has a three-way VOTcontrastforstops).Atotalof280tokenswithmissingvaluesforvariablesusedin themodelsbelow(listedinTable2)wereexcluded.EightytokenswithVOTsoutsideof 1–80msforvoicedstops,or8–175msforvoicelessstops,wereexcludedashavingex- treme VOTs, with the cutoffs determined by visual inspection of the distribution of VOT(separatelyforvoicedandvoicelesstokens).Becausespeechratehasalargeef- fectonVOTrelativetoothervariables,weexcludedsixty-twotokenswithaspeechrate greater than ten syllables/second as having extreme speech rates (presumably due to forced-alignmenterrors),withthecutoffdeterminedbyvisualinspectionofthedistri- butionofalltokens. ThefinalVOTdatasetconsistsof12,908voicedtokens(from788words,678clips) and12,246voicelesstokens(from964words,668clips),acrosstwentyspeakers. Coronalstopdeletion 3.2. .Coronalstopdeletion(a.k.a.t/d-deletion)isavariable processinEnglishinwhichword-finalcoronalstops(/t/and/d/)aresometimesdeleted inword-finalconsonantclusters(e.g.bestas[b s]vs.[b st]).6CSDhasbeenexamined ɛ ɛ indozensofstudies(usually)ofspontaneousspeechacrossmanyvarietiesofEnglish overthepastfiftyyears(reviewedinHazen2011,Schreier2005,Tagliamonte&Temple 2005).FewerstudieshaveexaminedCSDinBritishEnglishvarieties(e.g.Tagliamonte &Temple2005,Temple2009);particularlynotableisTagliamonteandTemple’sstudy ofYorkEnglish,whoseanalyticalchoicesweoftenfollow.Mostpreviousworktreats 6CSDisonetypeoffinalconsonantclusterreduction(CCR)inEnglishandthemostcommonlystudied. SeeHazen2011ontherelationshipbetweenCSDandCCR. Themedium-termdynamicsofaccentsonrealitytelevision 607 CSDasabinaryvariable,although‘deletion’isclearlyacategoricalapproximationfor gradientrealizationofcoronals(e.g.Temple2009).Weuseacategoricalbinarynotion of‘deletion’inordertomakeuseoftheresultsofpreviouswork—includingTanneretal. 2017,wheretheCSDdatasetdescribedbelowisanalyzedfromadifferentperspective, unrelatedtoourresearchquestionsabouttimedependence. Annotationanddataset .Annotationwascarriedoutbyfourphoneticallytrained annotators, for all speakers except Kathreya (twenty speakers), whose data was ex- cludedduetoanear-categoricaldeletionrate(presumablybecauseword-finalclusters ending in t/d are phonotactically illegal in Thai). Each token (n = 14,259) for these twentyspeakerswhoseunderlyingformendedinat/d-finalconsonantclusterwasman- ually annotated for the surface realization of the preceding consonant and the phono- logical context surrounding the final coronal, the length of any following pause (or other nonspeech), and the CELEX wordform ID (which was used to determine mor- phologicalclass),aswellastherealizationofthefinalcoronal.7 Coronalstoprealizationwasfirstannotatedatafine-grainedlevel,usingspectraland auditorycriteria.Annotatorschosefromeightcategoriesdescribingpossiblesurfacere- alizationsoft/d(usingtheacousticcuesofburst,glottalization,suddenclosure;realiza- tionasaglottalstop,anunreleasedcoronal,etc.).Incaseswheretheunderlyingt/dwas followedbyasurfacet/d(e.g.wantto),thetargett/dwastakentoberealizedonlyin cases where there was evidence for realization of a sequence of two distinct coronal stops.Ifthesecondt/dwasclearlypresentfollowingaclosure(usuallyduetothepres- enceofaburst)andnootherevidenceofaprevioust/drealizationwaspresent(suchas a glottal stop), the t/d was taken to be the realization of the following word, and the word-finalt/dwasannotatedasunrealized. Thefine-grainedannotationwasthencollapsedintoabinaryvariableofpresentver- susdeleted,followingpreviouswork(e.g.Tagliamonte&Temple2005),wherethepres- enceofanyunambiguousphoneticreflexoftheunderlyingt/dindicatespresence.We alsofollowedTagliamonteandTemple(2005)indiscardingalltokensendingin/rt/or /rd/inrhoticvarieties,giventhatmanyhousematesarespeakersofnonrhoticvarieties. Wefurtherexcluded141tokenswithoutaprecedingconsonantintheirsurfacereal- ization, twenty-two tokens where speech rate could not be reliably determined, one tokenwithannotationerrors,andfifty-ninetokensatturnends.Thislaststepwasnec- independent essaryinordertoincludepausedurationandfollowingcontextas factors affectingCSDrate,followingTanneretal.2017,wherethemotivationforthischoice (ratherthancodingpauseasanalternativefollowingcontext)isdiscussed. The final data set consists of 12,788 tokens (from 570 words, 667 clips), across twentyspeakers. Vowel formants. 3.3. Accents of English differ primarily in their vowels (Wells 1982).WithinagivenvarietyofEnglish,vowelqualityisdeterminedprimarilybythe goose strut firsttwoformants(F1,F2).WeconsideronlyvariationinF1andF2,for , , trap and . TherealizationofthesevowelsvariessystematicallyacrossEnglishdialectregions; thisvariationwillbeimportantforassessingwhetherfactorssuchassocialsalienceaf- fect medium-term time dependence.We describe the expected pronunciations of each 7Wedidnotmakeexclusionssuchasfrequent(e.g.and)orcontracted(e.g.don’t)forms,asinmuchpre- viousCSDwork,insteadaccountingforlexicaldifferencesusingby-wordrandom-effectterms.
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