TheSoundsofLanguage专题培训课件

LectureTwo

TheSoundsofLanguageIntroductionSomethinggeneralaboutphoneticsandphonologyPhoneticsisconcernedwiththedescriptionofspeechsoundsinalllanguages.Phonologyisconcernedwiththefunctioningofspeechsoundsindifferentlanguages.Phoneticsandphonologyhavemadethegreatestcontributionto“teaching”machinesto“talk”,bytellingthempreciselyhowtoproduceeachsoundinagivenlanguage.Humanbeingsarecapableofproducingawiderangeofsounds,butonlyasmallsetisusedforspeech.Thestudyofthespeechsoundsthatoccurinallhumanlanguagesiscalledphonetics.Phoneticsisthebranchoflinguisticswhichstudiesthecharacteristicsofspeechsoundsandprovidesmethodsfortheirdescription,classificationandtranscription.PartOnePhoneticsBranchesofphoneticsArticulatoryphonetics（发音语音学）Articulatoryphoneticsstudiesthehumanspeechorgansandthewayinwhichthespeechsoundsareproduced.Acousticphonetics(声学语音学)Acousticphoneticsdealswiththephysicalpropertiesofthespeechsounds;itstudiesthesoundwavesthroughtheuseofsuchmachinesasaspectrograph.

Auditoryphonetics（听觉语音学）Auditoryphoneticsisthestudyoftheperceptionofsoundsbythehumanear.Ofthethree,articulatoryphoneticsisthemosthighlydeveloped.ArticulatorsandtheirfunctionsTounderstandthenatureofalanguageitisnecessarytounderstandthenatureofitsspeechsoundsandhowtheyareproduced.Articulatoryphoneticsisthesubjectthatattemptstoprovideaframeworktodo

so.

Allthesoundswemakeduringspeakingaretheresultofmusclescontracting.Themusclesinthechestthatweuseforbreathingproducetheflowofairthatisneededforalmostallspeechsounds.Theairstreampushedoutbythelungsmovesupthroughthewindpipetothelarynx.Musclesinthelarynxproducemanydifferentmodificationsintheflowofairfromthechesttothemouth.Afterpassingthroughthelarynx,theairgoesthroughthevocaltract,theairpassagewhichisabovethevocalcords,andendsatthemouthandnostrils.Heretheairfromthelungsescapesintotheatmosphere.TheprocessofarticulatingThevocaltractcanbedividedintotheoralcavity,whichistheairpassagewithinthemouthandthethroat,thenasalcavity,whichistheairpassagewithinandbehindthenose,andthepharynx,whichisthecavityatthebackofthemouthandnose,wherethepassagestothenoseandtothemouthconnectwiththethroat.Theshapeofthevocaltractcanbechanged,e.g.bychangingthepositionofthetongueorthelips.Changesintheshapeofthevocaltractcausedifferencesinspeechsounds.ThevocaltractFigure1isusuallyusedinthestudyofphonetics.Itrepresentsthehumanhead,seenfromtheside,displayedasifithadbeencutinhalf.ArticulatorsandtheirfunctionsFigure1: Thearticulators

1.唇 2.齿 3.齿龈 4.硬腭5.软腭6.小舌7.舌尖

8.舌叶9.舌前部10.舌背11.舌根12.咽腔13.声带Esophagus/gullet

cavityatthebackofthemouthandnose,wherethepassagestothenoseandtothemouthconnectwiththethroat

ThevocaltractFigure2Figure3Figure4SummaryaboutthevocaltractThepharyngealcavity/pharynx(咽腔):betweenthetopofthelarynx(喉)andthesoftpalate)Thethroat(larynx)containsvocalcords/folds,ventricularfolds（膨胀带）andglottis(theopeningbetweenthevocalcords),themovementofwhichdeterminesthequalityofvoicing(voiced&voiceless(浊/清音))andpitch(音高).Thenasalcavity(鼻腔):thenoseNasalresonance(共鸣)canbeproducedduetotheloweringthesoftpalate(velum),resultingtheproductionofnasals.Theoralcavity(口腔):themouthItcontainsthelips,teeth,teeth(alveolar)ridge(齿龈/槽)tipoftongue,bladeoftongue,hardpalate,frontoftongue,backoftongue,softpalate(velum),uvula,epiglottis(会厌软骨).Thevelum

or

softpalateisseeninthepositionthatallowsairtopassthroughthenoseandthemouth.Itisoneofthearticulatorsthatcanbetouchedbythetongue.Whenwemakethesounds[k]and[g]thetongueisincontactwiththelowersideofthevelum,andwecallthesevelarconsonants.Thehardpalateisoftencalledthe“roofofthemouth”.Youcanfeelitssmoothcurvedsurfacewithyourtongue.Thealveolarridge

or

alveolumisbetweenthetopfrontteethandthehardpalate.Youcanfeelitsshapewithyourtongue.Itssurfaceisreallymuchrougherthanitfeels,andiscoveredwithlittleridges.Soundsmadewiththetonguetouchingheresuchas[t]and[d]arecalledalveolar.TheTongueisaveryimportantarticulator.Itcanbemovedintodifferentplacesandformdifferentshapes.Usuallyitisdividedintodifferentparts,thoughtherearenocleardividinglineswithinitsboundary.Figure2showsthetongueonalargerscalewiththesepartsshown:tip,blade,front,backandroot.Figure5:Sub-divisionsofthetongueTheteeth

(upperandlower)areusuallyshownonlyatthefrontofthemouth,immediatelybehindthelips.Thisisasimplifieddiagramshowingonlythefrontteeth,ignoringtheteethoneithersideofthemouth.Thetongueisincontactwiththeupperteethformanyspeechsounds.Soundsmadewiththetonguetouchingthefrontteetharecalleddental.The

lipsareimportantinspeechproduction.Theycanbepressedtogetherwhenweproducethesounds[p]and[b],broughtintocontactwiththeteethasin[f]and[v],orroundedtoproducethelip-shapeforvowelsas[uP].Soundsinwhichthelipsareincontactwitheachotherarecalledbilabial,whilethosewithlip-to-teethcontactarecalledlabiodental.Thesevenarticulatorsdescribedabovearethemajorones,buttherearethreeotherthingstoremember:(i)Thelarynxisalsoanarticulator,averyimportantandcomplexone;(ii)Thejawsaresometimescalledarticulators;surelywemovethelowerjawalotinspeaking.Butthejawsarenotarticulatorsinthesamewayasothers,becausetheycannotthemselvesmakecontactwithotherarticulators;(iii)Althoughthereispracticallynothingthatwecandowiththenoseandthenasalcavity,theyareaveryimportantpartofourvocalapparatusformakingsounds,particularlynasalconsonantssuchas[m]and[n].Again,wecannotreallydescribethenoseandthenasalcavityasarticulatorsinthesamesenseaswhatwehavediscussedabove.Itshouldalsobenotedthatwhatlinguistscallarticulatorsororgansofspeechhaveotherfunctionsevenmorecrucialforthesurvivalofhumanbeingssuchasbreathingandeating.Speechhasdevelopedasasecondaryuseoforgansalreadyinplaceforotherfunctions.VoicedandvoicelesssoundsThevocalcordsarelocatedinthelarynx,inwhatweperceiveas“Adam’sapple”(i.e.partofthelarynx).Thevocalcordsarelikecurtainsofmusculartissuethatcanbedrawnacrossthewindpipe.Whenthevocalcordsarespreadapart,theair-streamfromthelungsisnotobstructedatthespacebetweenvocalcordsandpassesfreely.Thesoundsproducedinthiswayaredescribedasvoicelesssounds.Thesounds[p],[t],[k],and[s]arevoicelesssounds.Whenthevocalcordsaredrawntogether,theair-streamforcesitswaythroughandcausesthemtovibrate.Soundsproducedinthiswayaredescribedasvoicedsounds.Thesoundsrepresentedby[b],[d],[g],and[z]arevoicedsounds.Vowelsareusuallyvoicedsounds.Thedistinctionbetweenvoicelessandvoicedsoundscanbefeltphysically.Youmaybeabletotellthedifferencebyrestingyourfingersonthetopofyour“Adam’sapple”asyoumakeeachsound.Ifyouproducesoundslike“z-z-z-z-z”youcanfeelsomevibrationbecausethesearevoicedsounds.Ifyouproducesoundslike“s-s-s-s-s”thereshouldbenovibrationbecausethesearevoicelesssounds.NasalandoralsoundsIfyousayrip[rip],rib[rib],andrim[rim],youwillnoticethatthefinalsounds([p],[b],and[m])areallproducedbyclosingthelips.[p]isdifferentfrom[b]becauseinproducingthevoiceless[p]thevocalcordsareapart;theglottisisopen.[b]isvoicedbecausethevocalcordsaretogetherandvibrating.Ifyouputyourhandsoveryourearsandkeepyourlipstogetherprolongingthepronunciationofthe[b]inribyouwillfeelthehumofthevibrationswhileyourlipsareclosed.Youwillnotfeelsuchvibrationsifyoukeepyourlipstogetherbeforereleasingtheminproducingthe[p]inripbecause[p]isvoiceless.Ifyoudothesameinproducingaprolonged“m-m-m-m-m”inrimyouwillseethat[m]isalsoavoicedsounds.What,then,distinguishes[m]and[b]?[m]isanasalsound.Whenyouproduce[m],airescapesnotonlythroughthemouth(whenyouopenyourlips)butalsothroughthenose.Whenthevelumisraisedallthewaytotouchthebackofthethroat,thepassagethroughthenoseiscutoff.Whenthenasalpassageisblockedinthisway,theaircanescapeonlythroughthemouth.Soundsproducedthiswayarecalledoralsounds.[p]and[b]areoralsounds.Whenthevelumislowered,airescapesthroughthenoseaswellasthemouth;soundsproducedthiswayarecallednasalsounds.Therearethreenasalconsonants[m],[n],and[D]inEnglish.Theseconsonantsareusuallyvoiced.Thesephoneticfeaturespermittheclassificationofallspeechsoundsintofourclasses:voiced,voiceless,nasal,andoral.Onesoundmustchoosetwoofthesefeatures,asshownbytheexamplesinTable1.Asyoucansee,therearenovoicelessnasalsinEnglish.Table1:ClassesofspeechsoundsOral

Nasal

Voiced

Voiceless

bdgptkmnClassificationofEnglishspeechsounds点击链接英语语音分类描述Variationsofsounds1)LiaisonAllEnglishwordswouldbeseparateunitsplacednexttoeachotherinsequence;inrealconnectedspeech,however,wesometimeslinkwordstogether.Themostfamiliarcaseistheuseof[r].Whenaword’sspellingsuggestsafinal[r],andawordbeginningwithavowelfollows,theusualpronunciationistopronouncethesecondwordwith[r].Forexample,theEnglishphrasehereareisoftenpronounced[hiLrL].Suchaphenomenonofthelinkingofwordsinspeech,inparticularwhenthesecondwordbeginswithavowel,iscalledliaison.Anotherexampleisthephraseaneggwhichisoftenpronounced[LQneg]withnonoticeablebreakbetweenthetwowords.2)ElisionandassimilationUndercertaincircumstancessomesoundsmaydisappear.Forexample,inrapidinformalspeechinEnglish,thewordsupposeisoftenpronouncedas[spLuz],factoryas[Qfæktri]andmostlyas[QmLusli].Thelossofasoundorsoundsinspeechliketheseiscalledelision.Thislossmaybeaconsonantorvowel.Elisionistypicalofrapid,casualspeech.Producingelisionsissomethingwhichstudentsofforeignlanguagesdonotneedtolearntodo,butitisimportantforustobeawarethatwhennativespeakersofEnglishtalktoeachother,quiteanumberofsoundsthattheweexpecttoheararenotactuallypronounced.Anothersignificantdifferenceinnaturalconnectedspeechisthewaythatsoundsbelongingtoonewordoronesyllablecancausechangesinsoundsbelongingtoneighbouringwordsorsyllables.Thisiscalledassimilation.Forexample,inEnglishthenegativeprefixoccursasim-beforewordssuchaspossible:impossible.Aspossiblestartswithabilabialsound,theprefix­im-endsinabilabialsound.Beforewordsliketolerant,however,theprefixisin-:intolerant.Astolerantstartswithanalveolarsound,theprefixin-endsinanalveolarsound.Asthefollowingsoundsbringaboutthechange,thisprocessiscalledregressiveassimilation.Ontheotherhand,thedifferencebetweenthe[s]intheEnglishword“cats”andthe[z]intheEnglishworddogsisanexampleofprogressiveassimilationbecausetheprecedingsoundsbringaboutthechange.PartTwoPhonologyBothphoneticsandphonologyareconcernedwiththesameaspectoflanguage----thespeechsounds.Buttheydifferfromeachother.Phoneticsisthebranchoflinguisticswhichstudiesthecharacteristicsofspeechsoundsandprovidesmethodsfortheirdescription,classificationandtranscription.PHONOLOGYisthebranchoflinguisticswhichstudiesthewaysinwhichspeechsoundsformsystemsandpatternsinparticularhumanlanguages.Phoneticsisgeneral,descriptiveandclassificatory.Itprovidesthemeansfordescribingandclassifyingspeechsoundsanddealswithhowspeechsoundsareactuallymade,transmittedandreceived.Phonology,ontheotherhand,dealsspecificallywiththewaysthosesoundsareorganizedinindividuallanguages,withitsprimaryaimbeingtodiscovertheprinciplesthatgovernthewaysoundsareorganizedinlanguages,andtoexplainthevariationsthatoccur.Phoneandphoneme

Phonesarethespeechsoundswehearandproduceinlinguisticcommunication.Phonemeisthesmallestunitofsoundinalanguagewhichcandistinguishtwowords.Phonesdonotnecessarilydistinguishmeaning.Butaphonemeisaunitthatisofdistinctivevalue.Itisnotanyparticularsound,butratheritisrepresentedorrealizedbyacertainphoneinacertainphoneticcontext.Phonemes:thephonologicalunitsoflanguagePhonologicalknowledgeenablesustoproduceallthephoneticallydifferentsoundsofalanguage.AspeakerofEnglishcanproducethesound[G]andknowsthatthissoundoccursinEnglish,inwordslike“thin”[Gin]and“bath”[bAPG].Healsoknowsthat[B],thevoicedcounterpartof[G],isasoundofEnglish,occurringinwordslike“then”[Ben],and“bathe”[beiB].Let’slookattheformsandmeaningsofthefollowingEnglishwords:(3)a.sip zipb.fine vinec.chunk junkHere,eachworddiffersfromtheotherwordsinbothformandmeaning.Thedifferencebetweensipandzipissignaledbythefactthattheinitialsoundofthefirstwordiss[s]andtheinitialsoundofthesecondwordisz[z].Theformsofthetwowords—thatis,theirsounds—areidenticalexceptfortheinitialconsonants.[s]and[z]canthereforedistinguishorcontrastwords.TheyaredistinctivesoundsinEnglish.Suchdistinctivesoundsarecalledphonemes.Weseefromthecontrastbetweenfineandvineandbetweenchunkandjunkthat[f],[v],[tF],and[dJ]mustalsobephonemesinEnglishforthesamereason—becausesubstitutinga[v]for[f]ora[tF]for[dJ]producesadifferentword.Asamatteroffact,inanylanguagewecanidentifyasmallnumberofregularlyusedsounds,vowelsandconsonants,forexample,thevowelsinthewordspinandpenaredifferentphonemesandsoaretheconsonantsatthebeginningofthewordspenandbet.MinimalpairsandsetsStrictlyspeaking,everysoundisdifferentfromeveryothersoundandeventheintendedrepetitionofasoundwillbedifferenteverytimeitisproduced.Ifweuseaninstrumenttomeasurethem,wecanseethateachsoundisuniqueintermsofpitch,loudnessandlengthaswellasquality.Butinphonology,someofthedifferencesareignored.Thephonologistisconcernedwithwhatdifferencesaresignificant,ortechnicallyspeaking,distinctive.Adistinctivedifferenceisonethatbringsaboutthechangeofmeaning.Inordertodeterminewhicharedistinctivesounds,thecustomarypracticeistosetupminimalpairs—pairsofwordswhichdifferfromeachotheronlybyonesound.Forexample,chunkandjunk,banandbin,betandbat,fanandvan,fineandvine,sinkandzinc,siteandsideareminimalpairsinEnglish.Notethatseedandsouparenotminimalpairsbecausetheydifferintwosounds:thevowelandthefinalconsonant;andneitherareteachandcheat,becausethetwoconsonantscomparedarenotinthesamepositioninthestring.Togiveamoreprecisedefinition,minimalpairsaretwowordswhichareidenticalineverywayexceptforonesoundsegmentthatoccursinthesameplaceinthestring.Sotheminimalpairtestorsubstitutiontestisthefirstruleofthumbtodeterminethephonemesofanylanguage,thatis,toseewhethersubstitutingonesoundforanotherresultsinadifferentword.Ifitdoes,thetwosoundsrepresentdifferentphonemes.Whenagroupofwordscanbedifferentiated,eachonefromtheothers,bychangingonephoneme(alwaysinthesameposition),thenwehaveaminimalset.Thus,aminimalsetbasedonthevowelphonemesofEnglishwouldincludefeat,fit,fate,fat,fought,andfoot,andonebasedonconsonantscouldhavebig,pig,rig,fig,dig,andwig.MinimalpairshavebeenusedfrequentlyintestsofEnglishasasecondlanguagetodeterminenon-nativespeakers’abilitytounderstandthecontrastinmeaningresultingfromtheminimalsoundcontrast.FreevariationWehavesaidthatwhenthesubstitutionofonesoundforanotherresultsinadifferenceinmeaning,thisissufficientevidencethatthetwosoundsrepresenttwodifferentphonemes.Butsometimesthechangeofonesoundintoanotherdoesnotproduceadifferentword,butonlyadifferentpronunciationofthesameword.SomeEnglishspeakerspronouncethewordeconomicsdifferently,thefirstvowelbeingeither[e]or[i].Thisdoesnotchangethemeaningofthewordeconomics.Whentwoormoresoundsoccurinthesamepositionwithoutanyapparentchangeofmeaningtheyaresaidtobeinfreevariation.Otherexamplesincludedirectandeither.Afamousexampleisanoldsongofthe1930swhichwasbasedonthenotionoffreevariation:Yousayeither[i:BLr]andIsay[aiBLr],Yousay[ni:BLr]andIsay[naiBLr],[i:BLr][aiBLr][ni:BLr][naiBLr]let’scallthewholethingoff.DistinctivefeaturesPhoneticsprovidesthemeanstodescribespeechsounds,showinghowtheydiffer,whilephonologytellsuswhichsoundsfunctionasphonemestocontrastthemeaningsofwords.Inorderfortwophoneticformstodifferandtocontrastmeanings,theremustbesomephoneticdifferencebetweenthesubstitutedsounds.Theminimalpairseal[siPl]andzeal[ziPl]showsthat[s]and[z]representtwocontrastingphonemesinEnglish.Theonlydifferencebetween[s]and[z]isavoicingdifference;[s]isvoicelessand[z]isvoiced.Itisthisphoneticfeaturethatdistinguishesthetwowords.VoicingthusplaysaspecialroleinEnglish(andinmanyotherlanguages).Italsodistinguishesfeelandveal[f]/[v]andcapandcab[p]/[b].Whenafeaturedistinguishesonephonemefromanotheritisadistinctivefeature(oraphonemicfeature).Whentwowordsareexactlyalikephoneticallyexceptforonefeature,thephoneticdifferenceisdistinctive,sincethisdifferencealoneaccountsforthecontrastordifferenceinmeaning.Inadditiontovoicing,placeofarticulationandmannerofarticulationarealsotheprincipaldistinctivefeaturesofconsonants.Forexample,thedistinctivefeaturesofvoicedstops[b],[d]and[g]inEnglishareshowninthefollowing:bdgstop+++voiced+++bilabial+__alveolar_+_velar__+Eachphonemeinthischartdiffersfromalltheotherphonemesbyatleastonedistinctivefeature.SyllablesandconsonantclustersWecannotjustputanygroupofsoundstogethertogetaword.Somesequencesarenotpossible,wecannotsay,forexample,[dait]inChinese,foritisnotaword.Ineverylanguagewefindthatthereareconstraintsonthesequencesofphonemesthatareused.Forexample,noEnglishwordbeginswiththeconsonantsequence[zbf]andnowordsendwiththesequence[Eh];noChinesewordsendwithconsonantsotherthan[n]and[D].Inphonologywemusttrytoanalyzewhattheconstraintsandregularitiesareinaparticularlanguage,anditisusuallyfoundhelpfultodothisbystudyingthesyllablesofthelanguage.TheEnglishwordbeautifulconsistsofthreespeechunits:beau-ti-ful.Theseunits,whichareoftenlongerthanonesoundandsmallerthanawholeword,arecalledsyllables.Syllablescanbedefinedbothphoneticallyandphonologically.Phonetically(thatis,inrelationtothewayweproducethemandthewaytheysound),syllablesareusuallydescribedasconsistingofacenterwhichhaslittleornoairflowandwhichsoundscomparativelyloud.Thecenterisusuallyavowel,e.g.[i]in[big].Beforeandafterthiscenter(thatis,atthebeginningandendofthesyllable),therewillbegreaterobstructiontoairflowand/orlessloudsound.Phonologically,syllablesaredefinedbythewayinwhichvowelsandconsonantscombinetoformvarioussequences.Vowelscanformasyllableontheirownortheycanbethecenterofasyllable,e.g.[e]in[bed]bed.Consonantsareatthebeginningortheendofsyllablesand,withafewexceptions(e.g.[l]in[QEpl]apple),donotusuallyformsyllablesontheirown.Asyllablemustcontainavowel(orvowel-like)sound.Themostcommontypeofsyllableinlanguagealsohasaconsonant(C)beforethevowel(V),oftenrepresentedasCV.Technically,thebasicelementsofthesyllablearetheonset(oneormoreconsonants)andtherimeorrhyme.Therimeconsistsofthevowel,whichistreatedasthenucleusorpeak,plusthefollowingconsonant(s),treatedasthecoda.Thestructureofsyllablescanbediagramedasfollows:syllableonsetrime(rhyme)

nucleus(peak)codaconsonant(s)vowelconsonant(s)

Figure5:SyllablestructureIntheEnglishwordbed[bed],[b]istheonset,[e]thenucleusand[d]thecoda.Syllableslikeme,byornohaveanonsetandanucleus,butnocoda.Theyareknownasopensyllables.Whenacodaispresent,asinthesyllableup,cup,atorhat,theyarecalledclosedsyllables.ThebasicstructuresofsyllablesfoundinEnglishwordsincludeV(I,a),CV(do,tea,key),VC(am,eat,at,of),CVC(bet,cat,dog,cup),CCVC(green,train,brain),VCC(eggs,east),CCCVC(strike),CVCC(nest)andCVCCC(next).Asyoucansee,thelasttwowordsstrikeandnestbeginorendwithtwoormoreconsonants.InEnglishsomewordsmaycontainasequenceoftwoormoreconsonantsinonesyllable,forexample,[spl]in[splendid]splendid.Sequencesofconsonantslikethisarecalledconsonantclusters.Consonantclustersmayoccuratthebeginningofaword(aninitialcluster),attheendofaword(afinalcluster),orwithinaword(amedialcluster).Forexample:Initialcluster:[spl]in[splEF]splashFinalcluster:[st]in[test]“test”Medialcluster:[str]in[peistri]pastryWemustrememberthattwoconsonantssidebyside,iftheybelongtotwodifferentsyllables,cannotformaconsonantcluster.Forexample,inthewordafter,[f]and[t]arenotaconsonantclusterastheybelongtotwosyllables.Thesameisinthecaseofmasterinwhich[s]and[t]areintwosyllables.Buttheconsonants[d]and[j]inthewordduring[djuLriD]formaconsonantclusterastheyoccurinasinglesyllable.Languagesdiffergreatlyinthewaysinwhichconsonantscanformclusters,andinwhichpositionsinthewordtheclusterscanoccur.Forexample,inSerbo-Croatian,therearemanythree-consonantclustersininitialpositionwhichdonotoccurinEnglish,e.g.[smr],[zdr],[zgr],[zdv].ButinEnglish,awordwhichbeginswiththree-consonantclustersalwaysobservesthreestrictrules:Thefirstconsonantmustbe[s].Thesecondphonememustbe[p]or[t]or[k].Thethirdconsonantmustbe[l]or[r]or[w]or[j].Theresultisthatallwordsbeginningwiththreeconsonantsarewordssuchasspring,scream,string,squeal,square,splendidorstew.WeneverfindEnglishwordssuchas*bdling,*sgtealor*wbtendid.SuprasegmentalfeaturesManysignificantsoundcontrastsarenottheresultofdifferencesbetweenphonemes,buttheresultofotherthings,forexample,stressandintonation.Stressandintonationbelongtosoundcontraststhatextendoverseveralsegments(phonemes),andsuchcontrastsarecalledsuprasegmentals.1)StressWhenawordhasmorethanonesyllable,oneofthemwillbepronouncedwithmoreprominencethanothers.Thisbringsustoanotherspeechsoundphenomenon,thatofstress.Thismaybeafixedfeatureofaword,andessentiallypartofitsform,sothatthereisnorealchoiceinitsplacement.InEnglish,forexample,thenounsweddingandpersonwillalwaysbestressedonthefirstsyllable,andtheverbsdecideandincreasewillalwaysbestressedonthesecond.ItisworthourwhiletonotethatitseemstobeageneraltendencyinEnglishtomarkthedifferencebetweennounsandverbsinthisway:nounshavefirstsyllablestress,verbssecond.Stressistheintensityorprominencegiventoasyllable.Pitchandlengthconstituteintensitywhichseemstodeterminestress.Stressvariesfromsyllabletosyllable.Syllableswhicharepronouncedmoreforciblythanneighbouringsyllablesaregenerallysaidtobestressed,ormoreaccurately,stronglystressedorpronouncedwithstrongstress.InEnglishstressisasignificantfactorsinceitisanessentialpartofwordshape.Wordseasilybecomeunrecognizableifthe“stress”iswronglyplaced.InEnglishandma