When you start learning about AAC, the terminology can feel overwhelming. Therapists, teachers, and online resources use specialized vocabulary, and much of it is never explained.
This glossary covers every term you're likely to encounter. Definitions are written in plain English. Bookmark this page and come back whenever you need a quick refresher.
The Glossary
AAC (Augmentative and Alternative Communication)
An umbrella term for all the tools, strategies, and methods that help a person communicate when speech alone isn't enough. "Augmentative" means it supplements existing speech. "Alternative" means it can replace speech entirely. Most people who use AAC rely on a combination of both.
Aided AAC
Any form of AAC that requires an external tool or device. Picture cards, communication boards, tablets with AAC apps, and dedicated speech-generating devices are all examples of aided AAC. Compare with unaided AAC, which uses only the body.
Aided Language Stimulation (ALgS)
A strategy where the communication partner points to symbols on the AAC system while speaking naturally. For example, a parent might tap the "want" symbol on a communication board while saying "Do you want more juice?" This teaches the child how to use the system by showing them in real time. Research by Goossens' (1989) illustrated how aided language stimulation can improve symbol comprehension and use. For a deeper look at this strategy, see our guide to aided language stimulation.
Alternative Communication
Communication methods used instead of speech. This applies when a person relies primarily on AAC rather than spoken words. In practice, many AAC users combine alternative methods with whatever speech they have.
Assistive Technology (AT)
Any device, piece of equipment, or system that helps a person with a disability do things they would otherwise find difficult or impossible. AAC devices and apps fall under the assistive technology umbrella, but AT also includes things like wheelchairs, hearing aids, and screen readers.
Augmentative Communication
Communication methods used alongside speech to make messages clearer or more complete. A child who says a few words but uses a tablet app to express longer thoughts is using augmentative communication.
Communication Board
A flat display showing symbols, pictures, words, or letters that a person can point to in order to communicate. Communication boards range from simple laminated sheets with a few pictures to complex layouts organized by topic. They can be low-tech (printed and physical) or part of a high-tech app.
Communication Partner
Anyone who communicates with an AAC user. Parents, siblings, teachers, therapists, classmates, and friends are all communication partners. The quality of AAC outcomes depends heavily on how communication partners interact with the AAC user, especially whether they model language on the system.
Core Vocabulary
A small set of high-frequency words that make up the bulk of everyday conversation. Words like "more," "stop," "want," "go," "help," and "no" are core vocabulary. Research shows that a few hundred core words account for the vast majority of everything we say. Core vocabulary is the foundation of most robust AAC systems. Learn more about why core words matter in AAC.
Dynamic Display
A screen-based AAC system where the available symbols change depending on what the user selects. Tapping "food" might open a page of food items. Tapping the back button returns to the main page. Most modern AAC apps, including SabiKo, use dynamic displays. This allows thousands of words to be available without overwhelming the user on a single screen.
Echolalia
The repetition of words or phrases heard from others. Echolalia is common in autistic individuals and is now understood as a meaningful stage of language development rather than meaningless repetition. Immediate echolalia repeats words right after hearing them. Delayed echolalia uses phrases heard previously, often in context. See also gestalt language processing.
Feature Matching
The process of selecting an AAC system based on a specific individual's abilities, needs, and preferences. Rather than choosing the most popular device, a speech-language pathologist evaluates factors like motor skills, vision, cognitive level, and communication goals to find the best match. Feature matching ensures the tool fits the person, not the other way around.
Fitzgerald Key
A color-coding system used to organize vocabulary on AAC devices. Each word category gets a specific color: people/pronouns (yellow), verbs (green), descriptors (blue), nouns (orange), social words (pink), prepositions/misc (purple), and articles/conjunctions (gray). The Fitzgerald Key helps users locate words faster because they learn to associate word types with colors. SabiKo uses Fitzgerald Key colors throughout its vocabulary layout.
Fringe Vocabulary
Words that are specific to a particular person, topic, or situation. Names of family members, favorite foods, classroom-specific terms, and hobby-related words are all fringe vocabulary. Fringe words are important for personalization but are used less frequently than core vocabulary. A well-designed AAC system balances both.
Gestalt Language Processing
A pattern of language development where a person learns language in chunks or whole phrases rather than individual words. A child might say "Let's go to the park" as a single memorized unit before understanding each word separately. Gestalt language processing is common in autism and is recognized as a valid developmental path (Blanc, 2012). AAC can support gestalt processors by including frequently used phrases alongside individual words.
High-Tech AAC
AAC systems that use electronic devices with speech output. This includes dedicated speech-generating devices, tablet apps, and computer-based systems. High-tech AAC offers advantages like voice output, large vocabularies, and dynamic displays. It requires power and charging, which is the main tradeoff compared to low-tech options.
IEP (Individualized Education Program)
A legal document in the United States that outlines the educational goals and services for a child with a disability. If a child needs AAC to participate in school, the IEP should specify what AAC system will be used, how it will be provided, and what support the child will receive to learn it. AAC can also be written into a child's goals within the IEP.
Low-Tech AAC
AAC tools that do not require batteries, charging, or electricity. Printed picture cards, communication books, letter boards, and choice boards are all low-tech AAC. These systems are durable, inexpensive, and always available. Many families use low-tech AAC alongside high-tech options.
Mid-Tech AAC
AAC tools that use simple electronics, typically with pre-recorded speech output. Single-message buttons (like a BIGmack switch) and multi-message devices with a limited number of recorded phrases fall into this category. Mid-tech devices are simpler than tablet-based apps but offer voice output that low-tech tools cannot.
Modeling
The practice of using the AAC system yourself to demonstrate how it works. When a parent taps "want" on the device while saying "Do you want more?", that's modeling. Modeling is the single most effective strategy for teaching AAC use. It shows the child what to do, when to do it, and why. Research consistently shows that children whose communication partners model AAC regularly make faster progress (Binger & Light, 2007). See our practical guide to AAC modeling at home for tips on getting started.
Motor Planning
The brain's ability to plan and execute a sequence of physical movements. In AAC, motor planning refers to learning the physical path to a word on the device. When symbols stay in the same location over time, the user develops motor memory and can find words faster without searching. This is why consistent symbol placement matters in AAC apps.
Multimodal Communication
Using multiple forms of communication together. A child might use speech for greetings, sign language to say "more" during meals, a picture board at school, and a tablet app for longer conversations. Multimodal communication is natural and encouraged. The goal is never to restrict someone to a single method.
Neural Voices
Computer-generated speech that sounds natural and human-like, created using neural network technology. Older text-to-speech systems sounded robotic and mechanical. Modern neural voices are much more natural, which helps AAC users feel that their device voice represents them. Some systems offer voices matched to age and gender.
Participation Model
A framework for AAC assessment developed by Beukelman and Mirenda. Instead of focusing on what a person can't do, the participation model looks at what activities and interactions a person wants to participate in, then identifies the barriers and selects AAC tools to overcome them. It shifts the focus from deficits to opportunities.
PECS (Picture Exchange Communication System)
A structured teaching protocol where a person learns to communicate by handing a picture card to a communication partner in exchange for the desired item. PECS follows six specific phases, starting with simple exchanges and building to sentence construction. It was developed by Bondy and Frost in the 1990s and is widely used, particularly in autism intervention. PECS is a specific program, not a generic term for picture-based communication.
Pragmatics
The social rules of communication. Pragmatics includes things like taking turns in conversation, staying on topic, understanding sarcasm, adjusting language for different listeners, and using appropriate greetings. AAC intervention often addresses pragmatic skills alongside vocabulary and language structure.
Presume Competence
The principle that every person is capable of learning to communicate, regardless of their diagnosis, test scores, or current abilities. Presuming competence means providing access to robust communication tools from the start rather than requiring a person to prove they're "ready." This principle is foundational to modern AAC practice and is endorsed by ASHA (American Speech-Language-Hearing Association).
Robust Vocabulary
An AAC system that includes enough words and word types to express a wide range of messages. A robust system includes core vocabulary, fringe vocabulary, letters for spelling, and options for different parts of speech. It allows the user to say things they've never been taught to say. Compare with limited systems that only offer a few preset messages or choices.
SGD (Speech-Generating Device)
Any device that produces spoken output for the user. This includes dedicated hardware devices (like those made by Tobii Dynavox or PRC-Saltillo) and software-based solutions like tablet AAC apps. In clinical and insurance contexts, "SGD" is the formal term. In everyday conversation, people often just say "their device" or "their talker."
Symbol Set
A collection of pictures or icons used to represent words and concepts in an AAC system. Different AAC systems use different symbol sets. Common ones include PCS (Picture Communication Symbols), SymbolStix, and Mulberry Symbols. The choice of symbol set can affect how quickly a user learns to recognize and use the system.
Text-to-Speech (TTS)
Technology that converts typed or selected text into spoken audio. In AAC, text-to-speech allows a device to "say" a message out loud when the user types it or selects symbols. The quality of TTS has improved dramatically with neural voice technology, making device-generated speech sound more natural.
Unaided AAC
Communication that uses only the body with no external tools. Gestures, facial expressions, body language, vocalizations, and sign language are all forms of unaided AAC. Everyone uses unaided AAC to some degree. For some people, unaided strategies carry most of their communication.
Visual Schedule
A sequence of pictures or symbols showing the steps of a routine or the events of a day. Visual schedules help with transitions and reduce anxiety because they make time visible and predictable. While not strictly AAC, visual schedules use the same symbol-based approach and are often introduced alongside AAC systems.
Vocabulary Organization
How words and symbols are arranged within an AAC system. Common approaches include organizing by category (food, people, places), by frequency of use (most common words on the home page), by grammatical function (Fitzgerald Key color coding), or by activity context (words for mealtime, words for playground). Good vocabulary organization makes words easy to find and supports motor planning.
Terms You Might Hear From Therapists
A few additional terms that come up in clinical settings:
- AAC evaluation. A formal assessment to determine what AAC system best fits an individual. Usually conducted by a speech-language pathologist with AAC expertise.
- Communication functions. The reasons a person communicates. Requesting, rejecting, commenting, asking questions, and greeting are all communication functions.
- Prompt hierarchy. A structured approach to providing help. Full physical assistance is the most supportive prompt. A verbal reminder is less. An expectant pause (just waiting) is the least. The goal is to fade prompts over time so the person communicates independently.
- Sabotage (communication temptation). Intentionally setting up a situation that motivates communication. Giving a child a sealed container they can't open "sabotages" the routine so they need to ask for help.
Keep Learning
This glossary covers the terms you'll encounter most often. As you dive deeper into AAC, you'll pick up additional vocabulary naturally through conversations with therapists and other families.
If you're just getting started, Download SabiKo free and explore a well-organized AAC system firsthand. Seeing these concepts in action often makes them click faster than any definition can.
Download SabiKo free and put these terms into practice.
References
- Banajee, M., DiCarlo, C., & Stricklin, S.B. (2003). Core vocabulary determination for toddlers. Augmentative and Alternative Communication, 19(2), 67-73.
- Binger, C., & Light, J. (2007). The effect of aided AAC modeling on the expression of multi-symbol messages by preschoolers who use AAC. Augmentative and Alternative Communication, 23(1), 30-43.
- Blanc, M. (2012). Natural language acquisition on the autism spectrum: The journey from echolalia to self-generated language. Communication Development Center.
- Goossens', C. (1989). Aided communication intervention before assessment: A case study of a child with cerebral palsy. Augmentative and Alternative Communication, 5(1), 14-26.