Breaking Down AAC Systems: Components, Vocabulary, and Access
Once you understand what augmentative and alternative communication (AAC) is, the next step is to explore the different parts that makeup AAC systems and strategies. For speech-language pathologists (SLPs), knowing these components is key to choosing and tailoring systems that meet each person's specific needs and communication goals. Knowing this can help parents and caregivers better support using AAC systems, working together with your SLP to ensure the system benefits your loved one.
The Components of an AAC System
AAC systems are as unique as the individuals who use them. Here are the core components that make these systems effective and adaptable:
Screen Options: No-Tech, Low-Tech, and High-Tech
No-Tech AAC: These systems do not rely on technology. Examples include picture boards, communication books, or simple written messages. They’re often portable, cost-effective, and easy to use (AssistiveWare, 2023).
Low-Tech AAC: These systems include static devices, such as boards with pre-printed symbols or buttons that produce limited recorded messages. They provide an entry point for individuals who need more structured communication tools.
High-tech AAC: These are advanced systems, such as speech-generating devices (SGDs) with dynamic screens, tablets with AAC apps, or devices that integrate eye-tracking. They offer the highest level of customization and can grow with the user’s needs (Lingraphica, 2023).
2. Symbol Types and Iconicity Symbols are a key part of AAC systems, representing words, ideas, or actions. Symbol types include:
Photographs are realistic images that clearly show the objects they depict. They work well for users who prefer symbols that resemble what they represent.
Pictographic symbols are simple drawings, like Boardmaker symbols. They are easy to understand and can be used in various situations.
Abstract Symbols, such as color-coded or arbitrary shapes, are less visually related to their meaning. They require higher cognitive skills to interpret but allow for more extensive vocabulary sets.
Why Iconicity Matters: Iconicity refers to how closely a symbol resembles its meaning. High-iconicity symbols are more manageable for beginners, while advanced users may benefit from abstract symbols to represent complex ideas.
3. Vocabulary Types: Core and Fringe Vocabulary
Core Vocabulary: These are high-frequency words that make up 70-90% of everyday communication, such as "I," "want," "go," and "help" (ASHA, 2023).
Fringe Vocabulary consists of specific words tailored to the individual’s needs, such as "soccer," "piano," or the name of a favorite snack (AssistiveWare, 2023).
Why Both Matter: Balancing core and fringe vocabulary ensures users can express themselves in general and personalized ways.
4. Display Organization: How vocabulary is arranged in an AAC system affects usability and efficiency. Common display types include:
Grid-Based Displays: Symbols are arranged in a grid, often grouped by category or part of speech.
Visual Scene Displays: The screen shows a photograph or scene with interactive "hotspots" for specific words or phrases.
Hybrid Displays: Combines elements of both grid-based and visual scenes, offering flexibility and ease of navigation.
5. Physical Access Methods: How people use their AAC system depends on their physical abilities. The ways they interact with it are called access methods, and these can include:
Direct Selection: Touching the screen or symbols directly is often the fastest method.
Scanning: The system highlights options sequentially, and the user selects by activating a switch.
Head Tracking: This method uses a device that follows the movement of the user’s head to select items on the screen.
Eye Tracking: Advanced systems track eye movements using a camera, allowing the user to choose symbols just by looking at them.
Who Can Benefit from AAC?
AAC is not one-size-fits-all but versatile enough to support many individuals. People with developmental disabilities (e.g., autism, cerebral palsy), acquired conditions (e.g., stroke, ALS), or temporary impairments (e.g., after surgery) can all benefit from AAC. SLPs are crucial in assessing, recommending, and customizing these systems to meet individual needs.
The Big Picture
Choosing or designing an AAC system involves understanding the user’s unique strengths, needs, and preferences. For SLPs, this means staying informed about the latest AAC tools and evidence-based practices. It also means partnering with professionals to ensure the system is functional and meaningful for parents and caregivers.
At The Big Picture SLP, we’re here to guide you through the world of AAC. If you’re a speech-language pathologist seeking mentorship, subscribe to our newsletter for updates and resources. Parents and caregivers, book a consultation today to explore how AAC can empower your loved one. Together, we can create a communication system that works for everyone!
References
American Speech-Language-Hearing Association. (2023). Augmentative and alternative communication. Retrieved from https://www.asha.org/public/speech/disorders/aac/
AssistiveWare. (2023). What is AAC? Retrieved from https://www.assistiveware.com/learn-aac/what-is-aac
Lingraphica. (2023). What is an AAC device? Retrieved from https://lingraphica.com/aac-devices/what-is-an-aac-device/
Communication Matters. (2023). What is AAC? Retrieved from https://www.communicationmatters.org.uk/what-is-aac/