Vowel Information in Postvocalic Fricative Noises

Abstract

When the postvocalic fricative noises of [s] and [f] are excerpted and combined with vocalic segments having inappropriate formant transitions, vowel quality, or both, the fricative percept is determined by the noise. However, there is often a perception of a diphthong in the vowel. This phenomenon was explored for the vowels [a, i, o, u] preceding the fricatives [s] and [∫]. In the first of two experiments, all combinations of the vocalic segments and fricative noises were presented for identification of the vowel. The perception of diphthongs occurred much more often on mismatches of vowel quality than of transition, indicating that there is substantial vowel information in the noise. In the second experiment, just the noises of the syllables were presented, with subjects trying to identify the missing vowel. The high vowels [i] and [u] were reliably identified, while identifications of [a] and [o] were at chance. This result agrees with previous studies of initial fricatives (Yeni-Komshian and Soli, 1981). Fricative noises from [i] and [u] were responsible for the large majority of diphthong percepts in Experiment 1. These results illustrate that fricative noises contain considerable information about preceding high vowels.