The study of language acquisition and processing and the practice of augmentative and alternative communication (AAC) intervention have a mutual beneficial impact. Each of the three major approaches in explaining language acquisition (rationalistic, empiricist, and functionalist) provides interesting perspectives in understanding the uniqueness of language acquisition through AAC. When looking at language processing, studies of AAC use can provide information on the multimodality and internal multimodal representational networks.
The study of the main language components (phonology, morphology and syntax, lexicon) in AAC users raises interesting questions concerning (a) the effect of the use of a speech-generating device on an internal phonology, (b) the relation between morphological and syntactic rules and communicative effectiveness, and (c) the effect of the use of communication boards and devices on lexical development and lexical growth.
AAC practice is a potential source of data that can lead to more effective intervention as well as to a better understanding of language processes in general.
