Non-speech communication symbols and systems: where have we been and where are we going?

During the past quarter century, and especially during the past decade, we have seen the emergence of various non-speech communication symbols and systems as viable means of communication by and with severely handicapped individuals. A brief overview of the full range of both aided (static or graphic) and unaided (dynamic or manual) non-speech symbols and systems is presented. A hierarchy of difficulty, cognitive requisites, approximation to English (or other natural languages), abstraction, acceptance, etc. is considered. Advantages of non-speech communication are related to general input simplification, response production, receptive language/auditory processing, stimulus processing/stimulus association, and symbolic representation. The advantages of vocabulary limits and attentional facilitation for intervention with severely handicapped individuals are discussed. Major research issues are also explored.