Examqo › Examqo library › Speech-language pathology and audiology › AAC
Building an AAC system: symbols, vocabulary, displays and access
An AAC system is built around the user: symbols as transparent as needed (tangible objects and photos for someone who struggles with symbols), a vocabulary of core words in fixed places alongside fringe words specific to his life, a display that matches his language stage, and direct access — and only when that is impossible, scanning.
Why it matters in the exam
Exam questions ask you to match a solution to a user: tangible objects suit people with severe cognitive impairment; the most transparent symbol for a sports shoe is a photograph of it; a visual scene display (a photo of an event from the user's life) suits toddlers, people with significant language limitations and adults with global aphasia; and a board of single words and simple sentences suits expressive aphasia. In advanced ALS with intact thinking and language, a spelling board is the default.
Vocabulary and access are asked too: core words are a small number of very frequent words used in many contexts, and fringe words are, for example, names of places and animals; to increase regular use, core words are placed in fixed positions; and a common reason a child does not use his system is that the vocabulary does not match his needs. Scanning suits a user who cannot select directly; a child with spastic quadriplegic cerebral palsy may operate a computer by head movement with visual scanning, and a child with a severe motor impairment and a severe visual impairment will select by auditory scanning with a partner.
Key points
- Symbols by transparency: objects and photos for severe impairment.
- Core words in fixed places; fringe words by the user's life.
- Visual scene: toddlers and global aphasia; spelling board: ALS with preserved language.
- Direct access first; scanning only when there is no choice.
- Non-use — usually a vocabulary that does not fit.
Summary table
| Component | Options | Who it suits |
|---|---|---|
| Symbols by transparency | Tangible objects, photographs, drawings, graphic symbols, letters | Objects — severe cognitive impairment; a photograph — the most transparent symbol |
| Core vocabulary | A small number of very frequent words that fit many contexts | In fixed positions on the board, to increase use |
| Fringe vocabulary | Names, places, animals, personal topics | Tailored to the user's life |
| Visual scene display (VSD) | A photo of an event from the user's life with hotspots | Toddlers, significant language limitation, global aphasia |
| Grid and schematic displays | Symbols in a grid; a display organised by activity or script | A verbal girl with low intelligibility; conversation on the activity topic |
| Direct selection | Pointing, touch, eye gaze | Preferred when possible |
| Scanning | Visual or auditory, with a switch or a partner | When direct selection is impossible; auditory when vision is severely impaired |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- What matters for the exam
The full version is open to subscribers of: Speech and hearing (communication disorders).
Subscriber? Read the full topic Plans and prices 25 free questions
Sources
- Beukelman & Light, Augmentative and Alternative Communication: Supporting Children and Adults with Complex Communication Needs, 5th edition (2020) — Symbols, vocabulary selection and access techniques
- Light et al., Augmentative and Alternative Communication, 2019 — Designing effective AAC displays for individuals with developmental or acquired disabilities
- ASHA Practice Portal, 2024 — Augmentative and Alternative Communication
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.