Effects of Repeated Listening Experiences on the Recognition of Synthetic Speech by Individuals With Severe Intellectual Disabilities

Abstract

To examine the perception of synthetic speech by individuals with severe intellectual disabilities using a closed-response format task. Participants were 14 individuals with severe intellectual disabilities and a group of 14 typical individuals. A between-groups design was used to compare the performance of the 2 groups on word identification accuracy and word latency tasks. Data were analyzed using a repeated measures design. The results indicated that the performance of a group of individuals with severe intellectual disabilities was significantly poorer (p<.05) than that of typical individuals on the word identification task. Data analyzed for practice effects indicated that individuals with severe intellectual disabilities demonstrated a significant reduction (p<.01) in their word latency scores across sessions. Furthermore, there was an absence of significant effect (p>.01) of stimulus type (i.e., repeated vs. novel), indicating that individuals with intellectual disabilities are able to generalize their knowledge of the acoustic-phonetic properties of synthetic speech to novel stimuli. This study indicates that persons with severe intellectual impairments become more proficient at recognizing synthetic speech as a result of repeated exposure to it. These results have significant clinical implications for people who use speech-generating devices.