Augmentative and Alternative Communication

Augmentative and Alternative Communication (AAC) refers "to an area of research, clinical, and educational practice. AAC involves attempts to study and when necessary compensate for temporary or permanent impairments, activity limitations, and participation restrictions of individuals with severe disorders of speech-language production and/or comprehension, including spoken and written modes of communication" (ASHA, 2005, p. 1).

Individuals with severe communication disorders and for whom gestural, speech, and/or written communication is temporarily or permanently inadequate to meet all of their communication needs use AAC.

Speech may be replaced or augmented by:
 * gesture and body language;
 * manual sign;
 * handwriting; and
 * communication aids.

Communication aids are devices developed or adapted for use by people with severe 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 graphic symbols such as Picture Communication Symbols (PCS) or Blissymbols. Some individuals use wheelchairs which can accommodate large communication devices; others walk and need small, light aids. Some have the funds to purchase high tech equipment such as Dynamyte (a speech generating device); others do not.

A communication aid may be as simple as a piece of cardboard with an empty potato chips-bag stuck on it to represent a desire for chips, or as complex as a laptop computer, controlled with a 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.

Terminology Used in AAC
Symbol: Something used to represent another thing or concept. For example, a picture or line drawing of a dog to represent dog.

Symbol Set: A set of symbol that is closed in nature; symbol set can be expanded, but it does not have clearly defined rules for expansion (e.g., Picture communication symbols).

Symbol System: A set of symbol; includes rules or a logic for the development of symbols (e.g., Blissymbols).

Speech Generating Device: An electronic assistive device that produces speech (e.g., Dynamyte).

Assistive Communication Device: Electronic or non-electronic aid or device that provides external assistance for communication.

AAC System: An integrated network of symbols, techniques, aids, strategies, and skills.

Symbols Categorization
Aided Symbols: Require some type of external assistance, aid, or device (e.g. photographs and simple line drawings).

Unaided Symbols: Require nothing external to the user's body to produce a message (e.g., gestures and sign languages).

Iconic Symbols: Readily depicts a referent.

Opaque Symbols: Very little or no visual relationship to it's referent.

Symbol Selection Techniques
Direct Selection: An individual points to the desired symbol using a finger or a headstick.

Scanning: An individual is offered choices of symbol, and he or she indicates choice by performing a pre-determined signal that informs the listner that desired symbol has reached or selected.

See also: Blissymbolics

Devices

 * DynaVox Technologies
 * Prentke Romich
 * Toby Churchill Limited (Lightwriters)
 * Words+
 * The Great Talking Box Company
 * Picture Communication Symbols (PCS)
 * Lingraphica