RESUMO
The purpose of this investigation was to determine the relative effects of three different Augmentative and Alternative Communication (AAC) speech output methods (word, sentence, mixed words and letters) on a listener's ability to summarize paragraph-length texts. Based on previous work on the discourse processing of synthetic speech, a monotonic trend in a listener's ability to accurately summarize texts produced by different output methods was hypothesized (word > sentence > mixed). Thirty able-bodied adults were individually tested over a 2-day period, listening to four texts produced by a DECtalk speech synthesizer at a speech presentation rate of 7.5 wpm. Using a discourse summarization taxonomy developed by Higginbotham, Lundy, and Scally (1993), the experimental hypothesis was confirmed. Word-method listeners produced significantly more accurate renditions of the original texts than sentence-method listeners, who, in turn, did better than mixed-method listeners. Statistically significant differences also were found for the topic familiarity of the texts. The role of the above variables on AAC device comprehension and technology design is discussed.