Augmentative and Alternative Communication (AAC) is a term used to describe various methods that supplement or replace typical speech and writing when these methods are impaired. AAC can be used for both expression and comprehension.
There are different forms of AAC systems and they are utilised effectively through comprehensive individual assessment, training, and careful selection of vocabulary and access methods.
Categorisation of AAC Systems
AAC systems are divided broadly into two main types: unaided and aided communication.
Unaided communication
Unaided communication does not require additional equipment. It can sometimes be unconscious, such as body language, or a deliberate part of communication, like gesturing.
Examples of unaided systems include:
- Body language (e.g., facial expressions and gesture).
- Vocalisations.
- Pointing and eye pointing.
- Signing Systems/Manual Signs: These are symbol systems based on manual signs or gestures. Signing is spontaneous, portable, and reliable because it requires no equipment.
- British Sign Language (BSL): Primarily used by the deaf community.
- Makaton Signs: A basic vocabulary based on BSL signs, used alongside spoken English, where only key words are signed. Makaton is now used by a wide range of people with complex communication needs.
- Signalong: Also based on BSL, signing is used concurrently with spoken English and follows the English word order, signing key words.
- Finger Spelling / Manual Alphabet: Uses hand positions to represent letters, available in two-handed (for the deaf community) or one-handed versions (for individuals with hemiplegia or deaf/partially sighted individuals).
- On body signs (for example Canaan Barrie): An adapted sign vocabulary for children with visual impairment and additional support needs, simplified to reflect everyday routines and interests, using body reference points and auditory feedback.
Aided communication
Aided communication uses equipment, ranging from paper based to electronic systems.
Aided Communication Systems
Paper-based aided communication systems offer a flexible and accessible starting point for individuals developing their communication skills:
- Pen and paper (to write or draw), alphabet based boards, charts and books for people who have literacy skills to spell and read.
- Communication charts or books utilizing pictures, photos, or symbols for people who have not developed the skills to spell or read yet. There are established symbol sets used in the UK which include Picture Communication Symbols (PCS)™, Widgit Symbols™, Symbolstix™, Makaton™, and Blissymbols™.
- Objects of Reference: Specific, real objects used to help someone choose or understand an upcoming event (e.g., a piece of seat belt to signify a car trip). The object should be relevant, may have multisensory properties, and should be consistent across settings.
Some systems are electronic which means they need power from batteries or mains supply and typically produce speech and/or text output. These can include:
- Equipment such as standard computers (laptops) or mobile devices (touchscreen tablets/iPads) running specialist communication aid software, or very sophisticated dedicated devices.
- Voice Output Communication Aids (VOCAs) which produce synthesized or recorded speech.
- Single Message VOCAs that are basic devices with a switch that speaks a single recorded message.
- Message Sequencer VOCAs that allow the user to activate a series of recorded messages sequentially with repeated switch presses.
- Overlay VOCAs which use paper/plastic overlays placed over keys/keyboards to represent static words or messages.
- Dynamic Screen VOCAs which display a keyboard, phrases, symbols or graphics on a screen that change dynamically based on the user’s selection (e.g., selecting a category opens a new page). These are suitable for both literate and non-literate individuals and can offer additional features like SMS, internet access, and viewing photographs.
Effective Utilization and Access Methods
Effective utilization of AAC systems involves a thorough assessment to match the system to the individual’s needs, abilities, and preferred method of access, along with ongoing training and support. There is no single “best” AAC system; many people use more than one, choosing which to use based on the situation and listener.
The Importance of Assessment and Clinical Decision-Making
Specialist advice is essential to identify the most appropriate AAC system(s).
- Assessment Process: An assessment determines a person’s needs for access techniques and technology and should be reviewed regularly as physical abilities change or new technologies become available. It is crucial before requesting funding.
- Multi-disciplinary Team: Assessment is ideally carried out by a team that may include a Speech and Language Therapist, Occupational Therapist, Physiotherapist, Teacher, Clinical Scientist, or Assistive Technologist.
- Clinical Decision-Making: Professionals reach a set of recommendations based on individual communication needs, consulting with the AAC user and their family. This process involves decisions about access systems, mounting systems, and intervention support structures.
- Deciding Factors: The choice of system depends on:
- Personal preference, abilities, and needs.
- Current and potential communication skills (e.g., literacy and spelling ability).
- Physical abilities and suitable access methods.
- Environmental factors and funding/cost.
Access Methods
Access methods are ways the user physically controls or selects input on an aided communication device or computer, aiming for the most efficient, reliable, and least tiring method. The choice of access method can be impacted by the user’s position, such as whether they are seated or in bed.
Direct Access Methods
Direct access involves the user immediately indicating what they want to select.
- Physical Selection: This includes pointing at a picture, typing on a keyboard, or activating a touchscreen. Users might use a fist or toes instead of a finger.
- Directed Gaze/Eye-pointing: Used by people with motor disorders, fixation (looking) replaces touch for selection. Where the selection is intentional, it is called ‘eye-pointing’.
- Eye-tracking or Eye-gaze Technology: Translates eye movement into mouse movement for computer or communication aid control.
- Head-pointing Devices: Worn on the head or glasses, movement is transmitted via infra-red or a tilt sensor, translated into mouse movement. Selection is made by “dwelling” or using a switch.
- Pointing Devices: Alternatives to a standard mouse, such as a trackball (rollerball), joystick, or single button mouse.
- Keyboard Adaptation: This includes adjusting keyboard response time, using a keyguard or touchguard to prevent accidental presses, or substituting standard keyboards with adapted ones (for example, expanded, compact, or ergonomic keyboards). Word prediction software reduces keystrokes needed by literate individuals.
Indirect Access (Scanning)
Indirect access is typically the best option for people with severe physical difficulties, requiring them to scan through options before selecting.
- Switch Control: The user activates a single or multiple switches, which controls a moving cursor on the screen.
- Switch Placement: The switch must be near a body part that the person can voluntarily control without excessive effort (such as a head, foot, knee, or hand).
- Switch Types: Switches range from those requiring light or no touch (proximity switches, useful for weak/restricted movements) to those requiring significant pressure (better for uncontrolled, strong movements). Some switches provide feedback (a click or a beep).
- Scanning Skill: Scanning is a demanding skill that requires a period of training and practice to learn switch pressing/releasing and error correction. The speed and type of scanning (such as scanning by row) can be adjusted.
Training, Support, and Conversation Strategies
Successful use of AAC depends heavily on training and ongoing support for the user, their family, and support staff.
- Learning Curve: Learning to use an AAC system effectively in conversation can take a long period of practice, similar to learning a foreign language. Seeing a ‘role model’ or mentor usng the same method is helpful.
- Communication Partner Role: Communication is a two-way process, and the person listening (the communication partner) is equally important. They must interpret the user’s reactions and expressions.
- Tips for Conversation: When talking with an AAC user:
- Allow more time than a typical conversation.
- Choose a quiet environment.
- Speak directly to the AAC user.
- Keep remarks short and simple, and avoid finishing the AAC user’s sentences.
- Be patient and wait for a reply.
- Ask open questions (who, what, why, how) to encourage detailed responses.
- Be prepared to clarify misunderstandings (for example, rephrasing or asking “Did you mean…?”).
- Be explicit when ending a conversation, as the AAC user may miss non-verbal cues if they are focused on their system.
