Augmentative and Alternative Communication

Description of the Strategy

Augmentative and alternative communication (AAC) is an area of educational and research practice focused on improving, either temporarily or permanently, the communication skills of individuals with little or no functional speech or handwriting ability. Because one AAC technique will never meet all of a person's communication needs, most individuals who rely on AAC use a combination of techniques, depending on the situation or communication partner; this approach is typically referred to as multimodal communication. The collection of techniques a person uses is referred to as his or her AAC system.

The most essential component of AAC systems is the symbols used to represent messages. A symbol is something that stands for or represents something else (the referent). Symbols can be divided into those that are aided, which require some type of external device for production, and those that are unaided, which can be produced with the person's body alone. Examples of aided symbols include real objects, photographs, and line drawings; examples of unaided symbols include facial expressions, manual signs, and vocalizations. The term iconicity is used to refer to the visual relationship of a symbol to its referent along a continuum. At one end of the continuum are transparent symbols, for which the shape, motion, or function of the referent can be readily guessed in the absence of the referent. At the other end are opaque symbols, in which no symbolreferent relationship is apparent, even when the meaning of the symbol is known. For example, a color photograph of a shoe is transparent, while the written word shoe is opaque. Between the two extremes are translucent symbols, in which the meaning of the referent may or may not be obvious, but a relationship can be perceived between the symbol and the referent once the meaning is provided. For example, the gesture commonly used in North America for “peace,” in which the second and third fingers are raised to form a “V,” is translucent in that one needs to be aware of the “V for victory” slogan used during World War II to understand its meaning. Generally speaking, transparent symbols are easier to learn and remember than those that are opaque, with translucent symbols lying between the two.

In addition to symbols, AAC systems involve various symbol display techniques for aided symbols. There are two general types: nonelectronic, or “lowtech,” displays and electronic, or “high-tech” displays. Nonelectronic display techniques include communication books, boards, wallets, or other devices that are neither battery operated nor computer based (such as date books and notepads). Electronic communication techniques require some type of external power source (e.g., batteries or electricity) to operate and produce output in the form of a screen display, printed page, or synthetic or digitized voice output. Some of these devices are complex and can be programmed with thousands of words or messages, while others are relatively simple to program and operate and may only contain a few words or messages. Many of the more sophisticated devices have additional features as well, including printers, calculators, large memory capacities [Page 1149]for storing lengthy text and speeches, and the ability to interface with standard computers.

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