Perception of dynamic information for vowels in syllable onsets and offsets

It has been demonstrated using the "silent-center" (SC) syllable paradigm t hat there is sufficient information in syllable onsets and offsets, taken t ogether, to support accurate identification of vowels spoken in both citati on-form syllables and syllables spoken in sentence context. Using edited na tural speech stimuli, the present study examined the identification of Amer ican English vowels when increasing amounts of syllable onsets alone or syl lable offsets alone were presented in their original sentence context. The stimuli were /d/-vowel-/d/ syllables spoken in a short carrier sentence by a male speaker Listeners attempted to identify the vowels in experimental c onditions that differed in the number of pitch periods presented and whethe r the pitch periods were from syllable onsets or syllable offsets. In gener al, syllable onsets were more informative than syllable offsets, although n either onsets nor offsets alone specified vowel identity as well as onsets and offsets together (SC syllables). Vowels differed widely in ease of iden tification; the diphthongized long vowels /e/, /ae/, /o/ were especially di fficult to identify from syllable offsets. Identification of vowels as "fro nt" or "back" was accurate, even from short samples of the syllable; howeve r, vowel "height" was quite difficult to determine, again, especially from syllable offsets. The results emphasize the perceptual importance of time-v arying acoustic parameters, which are the direct consequence of the articul atory dynamics involved in producing syllables.