Abstract
The purpose of this investigation was to determine the effects of the quality and speech presentation rate (SPR) of synthetic speech and textual characteristics (length, complexity, genre) on a listener's ability to summarize paragraph-length texts. Forty able-bodied students and staff members were individually tested over a 3-day period, listening to eight texts produced by one of two synthesizers (DECtalk, Echo+) at a normal SPR or with 10-second intervals of silence interspersed between individual words. Using a discourse summarization taxonomy developed for this study, subjects listening to DECtalk speech produced more accurate summaries than did ECHO speech listeners, and synthetic speech presented at a slow rate was summarized more accurately than synthetic speech presented at a normal SPR. Additionally, a significant three-way interaction effect was noted for voice × SPR × text complexity. Echo listeners performed more poorly at normal versus slow SPRs regardless of text complexity level. However, DECtalk listener performance declined only for complex texts presented at normal SPRs. Discussion focuses on the role of the above variables on the comprehension of voice output communication aids.