The purpose of this chapter is to review research conducted over the past two decades on the perception of synthetic speech by individuals with intellectual, language, and hearing impairments. Many individuals with little or no functional speech as a result of intellectual, language, physical, or multiple disabilities rely on non-speech communication systems to augment or replace natural speech. These systems include Speech Generating Devices (SGDs) that produce synthetic speech upon activation. Based on this review, the two main conclusions are evident. The first is that persons with intellectual and/or language impairment demonstrate greater difficulties in processing synthetic speech than their typical matched peers. The second conclusion is that repeated exposure to synthetic speech allows individuals with intellectual and/or language disabilities to identify synthetic speech with increased accuracy and speed. This finding is of clinical significance as it indicates that individuals who use SGDs become more proficient at understanding synthetic speech over a period of time.
