title: Producing American English vowels during vocal tract growth: a perceptual categorization study of synthesized vowels.
abstract: OBJECTIVE
  To consider interactions of vocal tract change with growth and perceived output patterns across development, the influence of nonuniform vocal tract growth on the ability to reach acoustic-perceptual targets for English vowels was studied.
  
  
  METHODS
  Thirty-seven American English speakers participated in a perceptual categorization experiment. For the experiment, an articulatory-to-acoustic model was used to synthesize 342 five-formant vowels, covering maximal vowel spaces for speakers at 5 growth stages (from 6 months old to adult).
  
  
  RESULTS
  Results indicate that the 3 vowels /i u ae/ can be correctly perceived by adult listeners when produced by speakers with a 6-month-old vocal tract. Articulatory-to-acoustic relationships for these 3 vowels differ across growth stages. For a given perceived vowel category, the infant's tongue position is more fronted than the adult's. Furthermore, nonuniform vocal tract growth influences degree of interarticulator coupling for a given perceived vowel, leading to a reduced correlation between jaw height and tongue body position in infantlike compared with adult vocal tracts.
  
  
  CONCLUSIONS
  Findings suggest that nonuniform vocal tract growth does not prevent the speaker from producing acoustic-auditory targets related to American English vowels. However, the relationships between articulatory configurations and perceptual targets change from birth to adulthood.
authors.affiliation: Département de Linguistique et Didactique des Langues, Université du Québec à Montréal, Succursale Centre-Ville, Montreal, Quebec, Canada. menard.lucie@uqam.ca
authors.forename: Lucie
authors.initials: L
authors.lastname: Ménard
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Davis
authors.forename: Louis-Jean
authors.initials: LJ
authors.lastname: Boë
authors.forename: Johanna-Pascale
authors.initials: JP
authors.lastname: Roy
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007568:Jaw / Q000502:physiology; D007804:Language Development; D010700:Phonetics; D011571:Psychoacoustics; D013060:Speech / Q000502:physiology*; D013067:Speech Perception; D014059:Tongue / Q000254:growth & development* / Q000502:physiology; D014825:Vocabulary; D014827:Vocal Cords / Q000254:growth & development* / Q000502:physiology; D055815:Young Adult