One of the very first faculties that is impaired after an individual suffers a stroke is communication. Lack of control over mouth and tongue. Blurred speech. Inability to form words coherently. Difficulties with understanding and comprehension. All these are, more often than not, the after-effects of suffering a stroke. A myriad techniques and theories have been tried out to solve this communication problem for stroke patients…and one of latest to be tried is Augmentative-Alternative Communication (AAC).
What is Augmentative-Alternative Communication (AAC)?
This is an umbrella term that encompasses communication methods used to supplement or replace speech or writing for those who are unable to produce or comprehend spoken or written language. AAC can be a permanent addition to a person's communication faculties or a temporary aid. However, studies have shown that AAC use is not a barrier in the development of speech, and may even result in a modest increase in speech production.
AAC is used to help people with a wide range of speech and language disabilities, not just for stroke patients, but also for:
- Congenital impairments such as cerebral palsy and Down’s Syndrome
- Intellectual impairment
- Acquired conditions such as Amyotrophic Lateral Sclerosis and Parkinson's disease
Modern use of AAC began in the 1950s with systems for those who had lost the ability to speak following surgical procedures. By the 1980s AAC emerged as a field in its own right. Advances in technology, including microcomputers and speech synthesis, paved the way for communication devices with speech output and multiple options for access to communication for those with extreme physical disabilities – Stephen Hawking being a case in point.
AAC: Many methods with one objective
AAC methods are diverse and varied. Basically, there are two types of communication methods.
- Unaided communication using no equipment. This includes sign and body language
- Aided communication methods which use external tools, including:
- Paper and pencil
- Communication books or boards
- Speech generating devices (SGDs)
- Devices producing written output
Tools used for aided communication
- Symbols include gestures, photographs, pictures, line drawings, letters and words - used alone or in combination
- Body parts, pointers, adapted mice, or eye tracking - used to select target symbols directly
- Switch access scanning used for indirect selection
Message generation is typically much slower than spoken communication hence rate enhancement techniques may be used to reduce the number of selections required.
Evaluation of a user's abilities and requirements for AAC
- The parameters to be considered before using AAC techniques include the person’s motor, visual, cognitive, language and communication strengths and weaknesses
- The evaluation takes into account inputs from family members, especially for early interventions
- Ethnicity and family beliefs are key to a family-centred and ethically competent approach
When and how to use assistive devices for stroke patients?
Difficulty in remembering and using spoken or written words, known as aphasia, is often a painful side effect of stroke. For some patients, that difficulty can last long after the stroke, causing severe impediments in their daily lives.
According to Assistant Professor of Communication Sciences and Disorders, Aimee Dietz, PhD, “For many post-stroke patients, aphasia does not completely erase their ability to communicate. Aphasia is a language disorder, meaning patients may have a hard time understanding what they read or hear and have difficulty expressing themselves when writing or speaking but often still have the ability to express themselves using fragmented speech.”
“Current rehabilitation practices typically do not introduce AAC devices until patients have plateaued in their language recovery”, says Dietz "Until we have a silver bullet for aphasia, we have to find some way for these patients to communicate.”
As part of her research, Dietz is studying when to introduce AAC technology into the rehabilitation process and how best to design the devices for patients.