Augmentative and Alternative Communication is the formal title for non-speech communication. In fact, the difference between augmentative and alternative communication is merely the difference between partial and total dependency on non-speech communication.

Speech may be replaced or augmented by:

 Communication aids are devices developed or adapted for use by people with severe expressive communication impairments.  Because these people have very varied skills, needs and problems there is a large range of communication aids.

Some people with severe communication impairments can use their hands; others cannot, and have to use alternatives such as mouth sticks, headsticks, switches or eye-pointing. Some can read and spell; others cannot, and need communication aids on which language elements are represented by pictures or symbols.  Some individuals use wheelchairs which can accommodate large communication devices; others walk and need small, light aids.  Some have funding to purchase high tech equipment; others do not.

A communication aid may be as simple as a piece of cardboard with 'no' and 'yes' written on, it or as complex as a laptop computer controlled with one switch which speaks and allows the user to talk on the phone, access the Internet or type an essay.

The best non-speech communication strategy (or combination of strategies) is the one which allows the person with severe communication impairment to communicate as freely as possible in as many situations as possible to the maximum number of people.

Nobody who has communication should be refused a trial of AAC resources to see if that would help.  The way to see whether someone will benefit from AAC therapy is to give them the therapy and see whether it works.