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Exam 1998 Question 6

" Explain how Voice Onset Time (VOT) varies across voiced and voiceless plosives in English and in one other language. Briefly describe an experiment to confirm that perception of VOT matches production of VOT in these two languages."

20 things you should mention:

  • V.O.T.
    • VOT is interval between release of pressure in syllable-initial plosive
      • and the start of vocal fold vibration for the following vowel
  • Language
    • in English there are two classes of plosive:
      • voiced plosives have simultaneous burst and voicing onset
      • VOT < 30ms
      • voiceless plosives have aspiration after burst
      • which delays VOT
      • VOT > 30ms
    • VOT also tends to be shorter in [b] than in [g]
    • in French, the contrast is different
      • voiced: pre-voicing, negative VOT
      • voiceless: de-voiced, small VOT < 30ms
      • due to weak/absence of aspiration
  • Experiment
    • record real instance of b/p from group of speakers of English/French
    • measure VOT values
    • synthesize extremes and continuum for perceptual test, e.g. Ball/Paul
    • random presentations to listeners of language
    • make forced choice between b/p
    • graph labelling behaviour as function of VOT
    • compare with production

© 2000 Mark Huckvale University College London