Augmentative and alternative communication is generally used as a single term. The most widely accepted and frequently used definition in this country was developed by the American Speech-Language-Hearing Association (ASHA):

Augmentative and Alternative communication is an area of clinical practice that attempts to compensate (either temporarily or permanently) for the impairment and disability patterns of individuals with severe expressive communication disorders (i.e., the severely speech-language and writing impaired). (ASHA, 1989)

Of course the scope and variability of severe expressive communication disorders is enormous. Alternative communication is used when one individual communicates in face-to-face communication with another individual in forms other than verbal speech. We are familiar with many of these forms which include sign language, graphic symbols, written words, Morse Code, etc.. These systems serve as alternative forms of communication for those who lack the ability to speak.

Augmentative communication means that there is a need for supplementary or supportive communication during face-to-face interactions. The word augmentative stresses the fact that training in alternative forms of communication is for the purpose of promoting and supplementing speech. Augmentative communication is available as an alternative form of communication if the individual does not or cannot begin to speak.

In summary, the major distinction is whether or not the communication system completely replaces speech (alternative) or supports and/or enhances speech (augmentative). That sounds simple enough but communication is never that simple. Communication is not a static process. There will be times when a gesture or facial expression or single sound communicates an entire idea. There may be times when just some support (augmentative) may be needed and there may be times when an alternative must be available.

Having functional and effective systems available is far more important than deciding whether or not a system is an alternative or augmentative one.