Augmentative and alternative communication (AAC)
From American Speech-Language-Hearing Association (ASHA) · source: asha.org
The American Speech-Language-Hearing Association's overview of AAC — what it is, who it helps, and the range of approaches from low-tech picture systems to dedicated speech-generating devices.
For decades, parents of non-speaking and minimally-speaking children were told that giving them an alternative to speech might make them less likely to speak. The opposite turned out to be true. Modern AAC — augmentative and alternative communication — is one of the clearest wins in autism support: it gives a child a voice now, and the research suggests it does not delay spoken speech and often supports it.
This piece covers what AAC actually is across its technology range, what the research says about its effects on spoken language, the specific systems families are likely to encounter, how to introduce AAC well, and the most common myths still circulating.
What AAC actually means AAC is anything that helps a person communicate without (or alongside) speech. It is not a single product. It covers: - Low-tech approaches: picture cards, communication books, sign language, gesture, written notes - Mid-tech: single-button voice output, simple cause-and-effect devices - High-tech: full speech-generating apps on a tablet (TouchChat, Proloquo2Go, LAMP Words for Life, CoughDrop, TD Snap), or dedicated speech-generating devices
Some children use one mode. Many use several at once — a sign for a quick request, a tablet for a longer thought, gesture and facial expression woven throughout.
What the research says about AAC and speech The persistent fear that AAC will "replace" speech — that giving a child a tablet will mean they never bother learning to talk — is one of the most thoroughly debunked claims in modern speech-language pathology.
The most-cited synthesis is Schlosser and Wendt's 2008 meta-analysis in the *American Journal of Speech-Language Pathology*, which reviewed every available study on AAC and speech development in autism. The conclusion was unambiguous: AAC does not inhibit speech, and in many cases supports it. A 2015 randomised trial by Romski and colleagues followed toddlers introduced to augmented communication at 18 months; the AAC group showed equivalent or better spoken-vocabulary outcomes than the speech-only comparison group at 24 months and beyond.
More recent work, including the body of research on gestalt language processing (Marge Blanc's work and the SLP communities building on it), has reframed the question further. For many autistic children — particularly gestalt language processors who acquire whole phrases before single words — AAC is not an "alternative" at all. It is the medium in which language develops.
Specific AAC systems families are likely to encounter Names get tossed around in clinic appointments. Here's what they are.
Low-tech - PECS (Picture Exchange Communication System). Developed in the 1980s by Bondy and Frost. The child hands a picture card to a communication partner to request items. PECS has good research support for early requesting; some critics note it can plateau if not paired with broader language work. - Communication books / boards. Bespoke, often laminated, paper-based systems where the child points to or selects from pictures or words. - Sign language and key word signing. Makaton (in the UK) and modified ASL signs (in the US) for foundational vocabulary. Often used alongside spoken language.
High-tech (speech-generating apps and devices) - Proloquo2Go (AssistiveWare). Probably the most widely-used AAC app on iPad. Symbol-based, customisable, with built-in robust vocabulary frameworks. - TouchChat with WordPower (Saltillo). Symbol-based, with the WordPower vocabulary designed around frequently-used words rather than nouns. - LAMP Words for Life (Forbes AAC). Built on motor planning principles — every word lives in the same place every time, so the body learns the path. - TD Snap (Tobii Dynavox). Highly customisable across user types and access methods, including eye-gaze for children with motor impairments. - CoughDrop. Open-source, browser-based, increasingly popular in schools.
Dedicated devices (Tobii Dynavox, PRC-Saltillo) are purpose-built hardware running AAC software — relevant when funding is available through health insurance or disability schemes, and when an iPad is not robust enough for the use case.
The right system depends on the child's motor profile, visual processing, cognitive style, and current vocabulary. A speech-language pathologist with AAC experience is the right partner for matching.
How AAC is introduced The strongest approach is one most families don't expect: introduce AAC before you wait to see if speech develops, not after. Even pre-verbal toddlers can begin to engage with AAC the same way they engage with spoken language — by being immersed in it. Adults model using the device in everyday situations (pressing "more" on the tablet while saying "more"), and the child gradually borrows what they see.
Two things matter more than which device is chosen: - Access — the device is in the room, charged, within reach, and not packed away after sessions - Modelling — the adults around the child use it themselves, often, for real communication
A device that lives in a school bag and only comes out in therapy will rarely take off. A device that lives on the kitchen counter, that the family uses while cooking and making decisions and laughing, has a real chance.
Aided language stimulation (the modelling approach) The single most evidence-supported way to make AAC succeed is something called *aided language stimulation* or *aided language input*. The idea is straightforward: adults use the AAC device while talking, in everyday situations, even (especially) before the child uses it themselves.
In practice: you press "more" on the tablet while saying "more" as you serve more pasta. You press "go" while saying "let's go." Over weeks and months, the child sees that the device is how the people around them communicate — not just a thing the speech therapist makes them use. The research base for aided language stimulation (Beukelman & Mirenda's textbook is the standard reference) is substantial.
A device that lives in a school bag and only comes out in therapy will rarely take off. A device that lives on the kitchen counter, that the family uses while cooking and making decisions and laughing, has a real chance.
What AAC is not AAC is not a sign of giving up on speech. It is not a tool for compliance. It is not a single button labelled "yes" to be pressed when an adult asks a question. Good AAC offers vocabulary that lets the child say things they actually want to say — including refusals, opinions, jokes, complaints, and "I love you."
Who decides what kind A speech-language pathologist with AAC experience is the right partner — not all SLPs have the training, and AAC is its own specialism. A good AAC assessment looks at the child's motor, visual, and cognitive profile and recommends a system that fits them, not the other way around.
Myths still circulating A short list of things families are sometimes told that the research does not support:
- "AAC will delay speech." The research consistently shows the opposite (Schlosser & Wendt 2008; Romski et al. 2015).
- "AAC is only for non-speaking children." Many speaking autistic children use AAC for moments when speech is hard — at the end of a long day, during meltdowns, in sensory-loud environments. Speaking sometimes is not the same as being able to speak always.
- "My child needs to prove they understand before getting a device." Presuming competence is the modern best-practice stance. Children are introduced to AAC and to speech in the same way: through exposure and modelling, not gatekeeping.
- "They'll just press random buttons." Children explore communication tools the way they explore language — by trying things out. That is learning, not misuse.
- "The device is too expensive to risk on a young child." Many families start with an iPad-based app rather than a dedicated device. Disability funding schemes in many countries cover AAC; ask your SLP.