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AAC includes both unaided and aided symbol systems.
- An unaided system is a system which only requires the communicator's body to. Unaided AAC systems include sign language, gestures, and other body movements, such as eye blinks or hand squeezes.
- An aided system uses an additional transmission device which may be either low-tech or high-tech. Low-tech systems include pictures, photographs, objects, line-drawings, icons, picture boards and communication books (e.g., PECS). High-tech systems include computer programs and voice output devices.
References:
American Speech-Language Hearing Association