Alternative and Augmentative Communication--What Is It?
People may have difficulty speaking due to a physical injury or a disability (e.g., cerebral palsy), a cognitive impairment (such as brain injury or autism), or both physical and cognitive disabilities. Some of these people use alternative and augmentative communication (AAC) strategies for communication. This article covers the general principles of AAC; more information about specific strategies is in our article about Alternative and Augmentative Communication--What are the Options?
AAC needs to be matched to the user's physical and cognitive capabilities, but also to the immediacy of their communication needs. If someone is trying to communicate, it is better to quickly provide simple but reasonably effective strategies, such as a sheet of paper with pictures that she can point to, than to wait until more sophisticated options are available.
AAC may be as simple as a device with a button that a user presses whenever appropriate to communicate a single message, e.g., "My name is Rachel and I'm happy to meet you." Slightly more sophisticated devices communicate multiple messages in sequence when a button is repeatedly pressed, e.g., parts of a knock-knock joke. If a user wants to communicate a variety of messages, or wants to be able to choose among two or more messages (e.g., yes/no), they will need a strategy that allows them to recognize and select the desired option at will.
AAC strategies that involve user selection may use graphics, words, or both. The graphics may be pictures or other literal representations (e.g., items from a fast food menu), or may be symbols that can be combined in various ways to make new words.
Literal use of graphics:
Symbolic use of graphics:
If the user's dexterity is also impaired, an AAC device may have buttons that require minimal effort to activate, or may work with alternative input methods such as switches. The user may point to options using a stick mounted via a strap to their hand or head, or held in their mouth.
Sometimes an AAC device is used along with speech, as it has been found to support the development of speech or can allow multi-modal communication.
If you meet someone who wants to communicate using AAC, try to understand how their system works, and be patient. It's okay to guess at the meaning they're trying to convey, but confirm your guesses instead of assuming. Here's more guidance on communicating with AAC users.