The perception of temporally modified conversational and clear speech by hearing-impaired listeners

Abstract

Hearing-impaired listeners find clearly articulated speech more intelligible than conversational speech [M. A. Picheny et al., J. Speech Hear. Res. 28, (1985)]. Acoustical measurements indicate that the temporal characteristics of clear and conversational speech differ [M. A. Picheny et al., J. Speech Hear. Res. (in press)]. In particular, clearly articulated segments are nonuniformly longer than the corresponding segments in conversational speech [R. M. Uchanski et al., J. Acoust. Soc. Am. Suppl. 1 77, S54 (1985)]. For example, the percent increase in duration for fricatives and diphthongs is much larger than that for short vowels and voiced plosives. To evaluate the importance of these temporal differences we have measured the intelligibility of two types of processed speech materials: conversational speech with nonuniformly increased segment durations and clear speech with nonuniformly compressed segment durations. Results from several hearing-impaired listeners will be discussed. [Work supported by NIH.]