Augmentative and alternative communication (AAC) overview​

Summary statement

Augmentative and alternative communication (AAC) should be considered as a viable option for improving the quality-of-life of anyone of any age with a severe communication impairment resulting from developmental, acquired, progressive, long-term or acute conditions.

(Last updated 2015)

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What is augmentative and alternative communication?

Augmentative and alternative communication (AAC) has been defined by the International Society for Augmentative and Alternative Communication (ISAAC):

“AAC is a set of tools and strategies that an individual uses to solve everyday communicative challenges. Communication can take many forms such as: speech, a shared glance, text, gestures, facial expressions, touch, sign language, symbols, pictures, speech-generating devices, etc. Everyone uses multiple forms of communication, based upon the context and our communication partner. Effective communication occurs when the intent and meaning of one individual is understood by another person. The form is less important than the successful understanding of the message”

AAC covers a huge range of techniques which support, or replace, spoken communication.

These include:

  • Gestures
  • Signing
  • Symbols
  • Word boards
  • Communication boards
  • Books
  • Voice Output Communication Aids (VOCAs) Communication Matters

Role of speech and language therapy in augmentative and alternative communication

If you or someone you know uses AAC, it is important to consult a speech and language therapist (SLT) or an AAC specialist to request a multi-disciplinary assessment to make an informed decision about any equipment that might be needed.

There is no ‘best’ type of AAC system. Each has pros and cons – the most suitable one for an individual will depend on their personal preference, situation and their abilities and needs. Specialist assessment will help to identify the most appropriate AAC system(s).


The RCSLT’s My Journey My Voice project provides information on AAC, a downloadable booklet and audio recordings of people using AAC.

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