What is AAC?

AAC stands for augmentative and alternative communication. It covers any way of communicating that doesn't depend on speech: hand signs, picture cards, a paper board, or an app that speaks words out loud.

The two words in the middle carry the meaning. Augmentative means it adds to whatever speech a child already has. Alternative means it can stand in for speech when there isn't any yet. It is not one product or one method. It's a category, and it's wide.

The two big families

Unaided AAC: just the body

Nothing to carry, nothing to charge. Hand signs, gestures, pointing, facial expression, looking at something on purpose. Baby sign language sits here. The advantage is that it's always with your child. The limit is that the people around them have to understand the signs.

Aided AAC: something outside the body

This runs from very simple to very complex:

• No-tech. A printed picture board, a small book of laminated cards, photos on a keyring. PECS-style picture exchange lives here.
• Low-tech. A single-message button a child presses to play a recorded phrase.
• High-tech. A tablet app or dedicated device that speaks the words aloud. These are often called speech-generating devices, or SGDs.

None of these is a step up from the other in a strict sense. A child can use signs, a picture board and an app in the same day, for different situations. Most do.

Words you'll hear from professionals

• SLP — speech-language pathologist, the professional who usually assesses and recommends AAC.
• SGD — speech-generating device, anything that speaks the message aloud.
• Symbol — the picture on a card. It might be a drawn icon or a real photograph.
• Modelling — using the AAC yourself while you talk, so your child sees how it works. This is the single practice most therapists ask parents to do.
• Robust AAC — a large system designed to give access to a full vocabulary, usually for children who are ready for many words and sentences.
• Core vocabulary — the small set of high-use words like more, go, stop, want that work across many situations.

Will AAC stop my child from talking?

This is the question almost every parent asks first, including me. The short answer is no: across four decades of research, studies have not found that AAC reduces speech, and most found the opposite. We wrote that up properly, with the citations and the limits, in Does AAC delay speech?

Where to start

If your child is very young, the practical question isn't which app has the most words. It's which system your child can actually use today without being overwhelmed. That's a different problem from the one most AAC systems are built to solve, and we cover it in AAC for toddlers.

Whatever you choose, involve a speech-language pathologist if you can. An assessment shapes the choice, and in many cases it's also what unlocks funding.

Common questions

What does AAC stand for?

AAC stands for augmentative and alternative communication. Augmentative means it adds to whatever speech a person already has. Alternative means it can stand in place of speech. It covers any method of communicating that does not depend on talking.

What is the difference between unaided and aided AAC?

Unaided AAC uses only the body: hand signs, gestures, facial expression, pointing. Aided AAC uses something outside the body, from a paper picture board to a tablet app that speaks words aloud.

Is my child too young for AAC?

There is no minimum age and no set of skills a child must prove first. Research has repeatedly found that so-called prerequisites are not supported, and AAC has been studied in toddlers under three. What changes with age is not whether AAC is appropriate but which system fits.