The American Speech-Language-Hearing Association (n.d.) suggests that acquisition and use of augmentative and alternative communication (AAC) is dynamic and that learning multiple modalities may be beneficial particularly for those individuals with severe disabilities. Evaluation of response variability after training multiple modalities has yet…

Various types of augmentative and alternative communication systems have been successfully used to enable functional communication in children with developmental disabilities. The effects of such systems on natural speech production have also been investigated, but few studies have explored the effects of specific procedures aim at inducing…