Toward functional augmentative and alternative communication for students with autism: Manual signs, graphic symbols, and voice output communication aids

Many individuals with autism are candidates for augmentative and alternative communication (AAC) systems, either to supplement (i.e., augment) their existing speech or to act as their primary (i.e., alternative) method of expressive communication. The purpose of this article is to summarize research and directions for future research with regard to two questions related to the delivery of AAC supports to these individuals: (a) What AAC modality is preferable to use? and (b) What do we know about the use of voice output communication aids with people with autism?.