articulatory Phonetics

14CHAPTER2Articulatoryphoneticsdealswiththecat-egorizationandclassificationoftheproduc-tionfeaturesofspeechsounds.Athoroughknowledgeofhowvowelsandconsonantsaregeneratedremainsessentialforsuccessfulas-sessmentandremediationofarticulatoryandphonologicaldisorders.Althoughcontempo-raryphonologicaltheorieshaveprovidednewwaysofviewingassessmentandtreatmentofthesedisorders,knowledgeofthespeechsounds’productionfeaturessecuresafirmba-sisforutilizingsuchprocedures.Withoutthisknowledge,phonologicalprocessanalysis,forexample,isimpossible.14ArticulatoryPhoneticsLEARNINGOBJECTIVESWhenyouhavefinishedthischapter,youshouldbeableto:Listthedifferencesinproductionandfunctionofvowelsversusconsonants.Identifythethreedescriptiveparametersthatareusedforvowelarticulations,andclassifythevowelsofAmericanEnglishusingthosethreeparameters.Differentiatebetweenmonophthonganddiphthongvowels.Definecenteringdiphthongs.Differentiatebetweenaphonemicandanonphonemicdiphthong.Identifythefourparametersthatareusedtodescribethearticulationofconsonants.Definethevariousmannersofarticulation.ClassifytheconsonantsofAmericanEnglishaccordingtotheirorgan,place,manner,andvoicingcharacteristics.Definecoarticulationandassimilation,anddescribethedifferenttypesofassimilatoryprocesses.Understandtheimportanceofsyllablestructureintheassessmentprocess.••••••••••2SPEECHSOUNDFORMch02.indd14ch02.indd147/12/20078:04:38AM7/12/20078:04:38AMARTICULATORYPHONETICS15Thischapterdiscussesarticulatory-phoneticaspectsofthespeechsoundsofGen-eralAmericanEnglish.Thespecificgoalsare1.toprovideareviewoftheproductionfea-turesofvowelsandconsonants;2.tointroducetheconceptsofcoarticulationandassimilationasameansofdescribinghowsoundschangewithinagivenarticu-latorycontext;and3.toexaminethestructureofsyllablesandtheirclinicalapplicabilityintheassess-mentandtreatmentofimpairedarticula-tionandphonology.Theproductionofvowelsandcon-sonants,andtheirsubsequentlanguage-specificarrangementsintosyllablesandwords,dependsonarticulatorymotorpro-cesses.Iftheseprocessesareimpaired,speechsoundproductionwillbedisordered.Articula-torymotorprocessesdependinturnonmanyanatomical-physiologicalprerequisites,whichincluderespiratory,phonatory,orresonatoryprocesses.Forexample,thespeechproblemsofchildrenwithcerebralpalsyoftenoriginateinabnormalrespiratory,resonatory,and/orphonatoryprerequisitesforarticulation.Theproperfunctionofsuchprerequisites,therefore,mustfirstbesecuredbeforeanyar-ticulatoryimprovementcanbeexpected.Ar-ticulatorymotorabilityisembeddedinmanydifferentanatomical-physiologicalprerequi-sites,whichareoffundamentalimportancetospeech-languagepathologists.Basicknowledgeintheseareasistypicallygainedfromcoursesandtextbookscoveringanat-omyandphysiologyofthespeechandhearingmechanismsratherthanfromthosecoveringimpairedarticulationandphonology.Thisisbecausetheclinicalsignifi-canceofanatomical-physiologicalknowledgeanditsapplicationtoarticulatoryandphono-logicaldisordersisnotalwaysrecognized.Theanatomical-physiologicalaspectsofsuchdis-ordersarenotwithinthescopeofthischap-ter.Box2.1offersreferencesasanincentiveforthereadertorediscoverthewealthofin-formationessentialtotheclinicalassessmentandremediationofarticulatoryandphono-logicalimpairments.VOWELSVERSUSCONSONANTSSpeechsoundsarecommonlydividedintotwogroups:vowelsandconsonants.Vow-elsareproducedwitharelativelyopenvocaltract;nosignificantconstrictionoftheoral(andpharyngeal)cavitiesexists.TheairstreamfromBOX2.1SelectedReadingsinAnatomyandPhysiologyoftheSpeechandHearingMechanismsCulbertson,W.R.,Cotton,S.S.,&Tanner,D.C.(2006).Anatomyandphysiologystudyguideforspeechandhearing.SanDiego:PluralPublishing.Kent,R.D.(1997).Thespeechsciences.SanDiego:SingularPublishing.Perkins,W.,&Kent,R.(1986).Functionalanatomyofspeech,languageandhearing:Aprimer.Bos-ton:Allyn&Bacon.Seikel,J.A.,King,D.W.,&Drumwright,D.G.(2005).Anatomyandphysiologyforspeechandlanguage(3rded.).CliftonPark,NY:Delmar.Zemlin,W.R.(1997).Speechandhearingscience:Anatomyandphysiology(4thed.).Boston:Allyn&Bacon.Formoreinformationabouttherespiratory,phonatory,resona-tory,andarticulatorycharacteristicsofcerebralpalsy,seeChapter10.ch02.indd15ch02.indd157/12/20078:04:40AM7/12/20078:04:40AM16CHAPTER2thevocalfoldstothelipsisrelativelyunim-peded.Therefore,vowelsareconsideredtobeopensounds.Incontrast,consonantsarepro-ducedwithasignificantconstrictionintheoraland/orpharyngealcavitiesduringtheirpro-duction.Forconsonants,theairstreamfromthevocalfoldstothelipsandnostrilsencoun-terssometypeofarticulatoryobstaclealongtheway.Therefore,consonantsareconsideredtobeconstrictedsounds.Formostconsonantsthisconstrictionoccursalongthesagittalmidlineofthevocaltract.Thisconstric-tionforconsonantscanbeexemplifiedbythefirstsoundintop,[t],orsoap,[s].For[t]thecontactofthefrontofthetonguewiththealveolarridgeoccursalongthismidlinewhilethecharacteristics-qualityismadebyairflowingalongthismedianplaneasthetongueapproximatesthealveolarridge.Bycontrast,duringallvowelproductionsthesagittalmidlineremainsfree.Inaddition,un-dernormalspeechconditions,GeneralAmeri-canEnglis