Symbol-based AAC

Symbol-based AAC refers to augmentative and alternative communication systems whose vocabulary is represented by graphic symbols, line drawings, photographs, or pictograms rather than (or alongside) written words. Users select symbols on a paper board, a dedicated speech-generating device, or a tablet app to compose messages, often with the device speaking the corresponding word aloud. Symbol-based AAC supports people with aphasia, intellectual disability, autism, cerebral palsy, and other conditions that affect spoken or written language, and is widely used by children before literacy. Common symbol sets include ARASAAC (open license, multilingual), PCS (Picture Communication Symbols), Widgit, SymbolStix, and Bliss. Selection of a symbol set affects vocabulary coverage, cultural appropriateness, and licensing of any tool built on top of it.