Augmentative and alternative communication, commonly abbreviated as AAC, refers to any method used to supplement or replace spoken language for people who have difficulty communicating verbally. AAC serves people with a wide range of conditions, including cerebral palsy, autism, ALS, stroke, traumatic brain injury, and various speech and language disorders. The term covers everything from simple picture boards to sophisticated speech-generating devices controlled by eye movement.

“Augmentative” communication supplements existing speech that may be difficult to understand, while “alternative” communication replaces speech entirely for people who are nonverbal or have very limited verbal ability. In practice, most AAC users rely on some blend of both, adjusting their communication method to the situation and the listener.

Types of AAC

AAC methods are generally grouped into two broad categories:

  • Unaided AAC: Communication methods that don’t require any external tool or device, such as sign language, gestures, facial expressions, and vocalizations. These rely entirely on the body.
  • Aided AAC: Communication methods that use a tool or device external to the body. This category spans a wide spectrum:
    • Low-tech aided AAC: Picture boards, communication books, and letter boards that a user points to or that a communication partner scans through
    • High-tech aided AAC: Dedicated speech-generating devices (SGDs) or tablet-based apps that convert selected symbols, words, or typed text into synthesized speech

High-tech AAC devices are often controlled through methods adapted to the user’s physical abilities, including direct touch, head pointers, eye-gaze tracking, or switch access, where a user activates a single switch to scan through and select options.

Who uses AAC

AAC serves people across a wide range of ages and conditions:

  • Children with developmental disabilities, including autism spectrum disorder, who may develop AAC use alongside or as a bridge toward spoken language
  • People with degenerative conditions like ALS, where AAC use often increases over time as speech becomes more difficult
  • Stroke survivors with aphasia, who may use AAC temporarily or permanently depending on their recovery
  • People with cerebral palsy or other conditions that affect the muscles used for speech, while cognition and language comprehension remain unaffected

A common misconception is that AAC use signals limited intelligence or comprehension. In reality, AAC exists precisely because a person’s capacity to think and understand language often outpaces their physical ability to produce speech.

AAC and web accessibility

AAC intersects with web accessibility in a few concrete ways. Many AAC users navigate computers and websites using the same alternative input methods they use for communication — switch access, eye-gaze systems, or head pointers — rather than a standard mouse. A website that depends on precise mouse movements, hover-triggered menus, or short time limits creates the same barriers for these users that it does for anyone using assistive input devices generally.

Structured, predictable content also matters more for some AAC users, particularly those with co-occurring cognitive disabilities: clear headings, plain language, and consistent navigation reduce the cognitive load of parsing a page, similar to considerations that apply broadly to cognitive accessibility.

How accessiBe’s platform supports AAC users

accessWidget — accessiBe’s AI-powered accessibility interface — includes adjustments aimed at users with cognitive and motor impairments, including simplified navigation, focus and orientation adjustments, and a built-in dictionary for unfamiliar words, which can reduce friction for some AAC users browsing a site, though it doesn’t interface directly with AAC devices themselves. Since AAC users often rely on the same underlying input methods as switch and keyboard-only users, the structural fixes that matter most — proper labeling, logical focus order, and full keyboard operability — are the kind of code-level issues accessFlow is built to catch and track across a site’s development pipeline.