The time course of vowel context effects

Abstract

At previous meetings of the Society we presented evidence for the existence of two different perceptual mechanisms mediating anchor‐induced contrast effects found with vowels. Extra presentations of an [i] endpoint to subjects identifying an [i]‐[I] series caused changes in sensitivity. Anchoring with [I] produced criterion shifts which were dependent on the availability of auditory memory. Since [i] and [I] differ in tenseness, intrinsic duration in natural speech, and acoustic status (point versus nonpoint), the differences in perceptual effects of these vowels cannot be ascribed to any one factor. To explore the role of these variables in vowel context effects, a number of different vowel series from different parts of the vowel space have been examined using a successive contrast paradigm. In this procedure, a context vowel is presented first, followed at varying temporal intervals by a test vowel. Results obtained using this procedure provide new evidence concerning the perceptual mechanisms underlying vowel anchor effects. Further, the pattern of these results obtained with different vowel series have important implications for theories of vowel perception. [Work supported by NSF and NIMH.]