Each of the following is a challenge particular to users of augmentative or alternative communication (AAC) not faced by natural communicators EXCEPT
◦ There are no systems that allow for expression of complex, abstract thoughts.
◦ Users of AAC who are not literate must rely on a vocabulary and symbols selected by others.
◦ AAC is much slower.
◦ AAC must be constructed to be useful in a variety of social contexts, allow efficient communication without undue fatigue, and support learning of language and academic skills.