On Defining the Vowel Duration That Cues Voicing in Final Position

Most investigations into the perceptual relevance of vowel duration have employed patterns of synthetic speech in which only the steady-state portions of syllables have been used as the variable. The experiments reported here were designed to discover if CV transitions are also included by the listener in determining the effective duration of the "vowel." More specifically, they measured the contribution of syllable-initial formant transitions to that "vowel" duration on which the voicing of a stop in syllable-final position can be made to depend. It is clear from the results that the syllable-initial transitions do contribute to that duration; indeed, they appear to contribute to the same degree as an equal duration of steady-state. Apparently, the effective duration of a vowel extends over all parts of the acoustic signal that may be said to have been influenced by it, including especially the transitions that reflect the consequences of the coarticulation of vowel and consonant.