Perceptual accommodation to sinewave speech.

Abstract

Many studies have reported good intelligibility for sine wave replicas of sentences (e.g., R. Remez et al., Science 212, 947–950 (1981)]. Recent work, however, has shown poor intelligibility (∼55%) for vowels in isolated syllables [J. Hillenbrand and M. Clark, J. Acoust. Soc. Am. 123, 3326 (2008)]. While enhanced intelligibility for sentences undoubtedly reveals the importance of top‐down mechanisms, it is also possible that sentence‐length utterances allow listeners to make (as yet unknown) perceptual accommodations to the unfamiliar acoustic properties of sine wave speech (SWS). In this study, the intelligibility of SWS replicas of 16 vowels/diphthongs in isolated syllables (“heed,” “hid,” and “hide”) was compared to that of the same syllables when preceded by a seven‐word SWS carrier phrase (CP) spoken by the same talker. Intelligibility was ∼24 percentage points higher when the SWS syllables were preceded by the SWS CP than when the same utterances were presented in isolation. Furthermore, the effect was observed even when the CP and test‐syllable talkers did not match, showing that the effect involves more than just talker normalization. Finally, a same‐talker natural speech CP preceding the SWS syllable produced a decrement rather than an improvement in intelligibility.