People who have communication disabilities

Communication is an interactive, two-way process that includes both understanding and being understood. Communication involves a range of communication methods in face-to-face interactions, over the telephone, online and via reading and writing. Communication methods include speech, gestures, body language, writing, drawing, pictures, symbol and letter boards, speech-generating devices, as well as human services such as ASL/LSQ/ISL interpreting, captioning in real time, informal and formal communication assistance.


There are over 440,000 Canadians who have significant speech, language and communication disabilities that are not caused by significant hearing loss.

The Participation and Activity Limitation Survey (PALS), 2001 suggested approximately 1.5% Canadians older than age 4 years have difficulty speaking and being understood.  In the USA, it is estimated that 1.3% of the population over 15 years of age experience difficulty having their speech understood.  In the UK, a study found that 1.4% of the population has a severe communication disability that makes it difficult for people to be understood, outside of the immediate family.

The prevalence of communication disabilities varies considerably with age.  A study in Canada suggests a rate of 0.8% for the population age 45 to 54 years and 4.2% for people 85 years and older.

Some are life-long disabilities, such as cerebral palsy, autism spectrum disorder, Down syndrome, a learning disability, or cognitive disability. Others are acquired disabilities such as traumatic brain injury, aphasia after a stroke, dementia, Amyotrophic Lateral Sclerosis (or ALS), Parkinson’s disease, Multiple Sclerosis.

Having a significant communication disability can affect one or more communication areas such as a person’s ability to speak, understand what others are saying, read and/or write.

People with speech disabilities may have slurred or unclear speech; or they may have no speech and communicate using gestures, pictures, letter boards, communication devices or assistance from a person who knows them well. They may use a voice amplifier if they have a weak voice. People with language disabilities may have difficulty hearing what people are saying or they may hear but have difficulty processing or understanding what another person is saying. For example, people who have aphasia after a stroke or accident may have difficulty in understanding others, and in speaking, reading and writing. People who have intellectual disabilities from birth or who acquire dementia or Alzheimer’s disease later may have problems remembering, learning, understanding, or problem-solving, making communication challenging. 

In addition to having communication challenges, many people have multiple disabilities. For example, people who have cerebral palsy may be unable to speak, walk or physically manipulate objects. People who have autism may experience challenges learning and using language, as well as interacting with other people. 

While some communication disabilities are easily observable (e.g. person who cannot speak and uses a device to communicate), others may be invisible. For example, a minor stroke or a learning disability can have a profound impact on a person’s ability to comprehend spoken language or express their own messages, especially in a stressful situation or when complex language and abstract concepts are required.