Producing American English vowels during vocal tract growth: a perceptual categorization study of synthesized vowels

J Speech Lang Hear Res. 2009 Oct;52(5):1268-85. doi: 10.1044/1092-4388(2009/08-0008). Epub 2009 Aug 20.


Purpose: 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.

Method: 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.

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Humans
  • Infant
  • Jaw / physiology
  • Language Development*
  • Phonetics*
  • Psychoacoustics
  • Speech / physiology*
  • Speech Perception
  • Tongue / growth & development*
  • Tongue / physiology
  • Vocabulary*
  • Vocal Cords / growth & development*
  • Vocal Cords / physiology
  • Young Adult