This information is provided as a reference to support you in understanding how different disabilities can affect a person’s speech, language and communication abilities. It is by no means a comprehensive list and is not intended to replace professional assessments, diagnoses and treatments by health care professionals.
Some of the disabilities listed here affect a person’s ability to understand what others are saying, which involves listening, attention, memory and processing abilities. Some disabilities affect how a person can communicate their message through speaking, pointing at pictures, writing, letter boards or devices. Some disabilities affect both comprehension and expression and can range from mild to severe.
People can also have dual and multiple disabilities that affect more than their communication skills. For example, some people may also have an intellectual disability, a physical and mobility disability, hearing loss, visual impairment or a mental health disability.
It is important to note that everyone is unique, and disabilities affect people in different ways.
DisabilityPossible effects on communication
|Cerebral Palsy||Cerebral palsy is a disorder that affects a person’s movements. Their speech might be slurred, unclear or they may have little or no speech and communicate using pictures, letters, symbols or a communication device. The person may or may not have difficulty walking and physically manipulating things. Most people who have cerebral palsy can understand what people are saying and make their own decisions. However, some people who have cerebral palsy may also have an intellectual disability.|
|Autism Spectrum Disorder||Autism spectrum disorder (ASD) is a life-long neurological disorder that can affect the way a person communicates and relates to the people and world around them. ASD can affect behavior, social interactions, and one’s ability to communicate verbally. ASD is a wide spectrum disorder, which means that while all people with ASD will experience certain difficulties, the degree to which each person on the spectrum experiences these challenges will be different.|
|Fetal Alcohol Spectrum Disorder (FASD)||Fetal Alcohol Spectrum Disorder (FASD) is a general term that describes the range of neurological and behavioral challenges that may affect a person if the person’s birth mother drank alcohol while she was pregnant. Individuals with FASD may have difficulties with learning, memory, attention span, problem solving, speech, and hearing.|
|Intellectual or Developmental Disability||Intellectual or developmental disability is a disability that can be caused by any condition that impairs the development of the brain, before birth, during birth, or in childhood and adolescence. The condition maybe be caused by genetic or inherited factors such as Fragile X Syndrome, Down Syndrome or other chromosomal abnormality; problems during pregnancy such as maternal infection, or maternal alcohol ingestion; problems at birth, such as premature delivery or oxygen deprivation; childhood diseases or head injury. Developmental disabilities can be mild, moderate, severe or profound. They are characterized by significant limitations in both intellectual functioning and in adaptive behavior. Intellectual functioning refers to learning, reasoning, problem-solving skills. Adaptive behavior is the collection of conceptual, social, and practical skills that are learned and performed by people in their everyday lives such as communication, literacy, money, time, number concepts, self-direction, safety, ability to follow instructions and other areas. People with intellectual disabilities may require support to understand questions and communicate their messages.|
|Dual Disability or Multiple Disabilities||People can have co-existing conditions. For example people with intellectual or developmental disabilities can also have motor, hearing and visual impairments, or mental health illnesses.|
|Speech disorders||Speech disorders affect how a person pronounces words. There are different types of speech disorders. Apraxia affects how a person moves and sequences their lips, tongue when speaking. Dysarthria is a weakness of muscles and can result in slurred speech or no speech.|
|Stuttering||Stuttering affects the fluency of speech. It is characterized by disruptions in the production of speech sounds.|
|Aphasia||Aphasia results from damage to the parts of the brain that contain language. Aphasia may cause difficulties in speaking, listening, reading, and writing, but does not affect intelligence. Aphasia is most often caused by stroke. However, any disease or damage to the parts of the brain that control language can cause aphasia. These include brain tumors, brain injury and progressive neurological disorders.|
|Amyotrophic Lateral Sclerosis (ALS)||ALS, sometimes called Lou Gehrig’s disease, is a progressive brain disease that attacks the nerve cells that control muscles. ALS can result in a person having unclear or no speech. A person with ALS may use a communication device. ALS does not affect a person’s intelligence, memory or the ability understand what is being said.|
|Dementia||Dementia is a group of symptoms related to memory loss and overall cognitive impairment. People with dementia may have difficulty processing what is being said to them, remembering, finding the words they want to say, attending to conversations and problem solving. There are different types of dementia such as Alzheimer’s Disease and Vascular Dementia.|
|Huntington’s disease||Huntington’s disease is an inherited disease that results in difficulty in movement, thinking and behavior. Speech may be slurred or the person may have little or no speech. A person may need to use a communication display or device. Communication difficulties may also cause problems with memory, sequencing, and problem solving.|
|Brain Injury||There are different types of brain injuries. These injuries can be caused by a stroke, tumors, infection, and traumatic brain damage. Depending on the location and severity of the damage, communication functions that can be affected include speech, understanding of language, attention, memory, perception, reasoning, organizational skills, social interactions, insight, and problem solving, behavior, reading and writing.|
|Stroke||A stroke can cause paralysis or muscle weakness, loss of feeling, speech and language problems, memory and reasoning problems, swallowing difficulties, problems of vision and visual perception. Communication deficits may include difficulty in understanding or producing speech correctly such as in aphasia; slurred speech due to weak muscles and/or difficulty in programming oral muscles for speech production.|
|Selective Mutism||Selective Mutism usually happens during childhood. A child with selective mutism does not speak in certain situations.|
|Head and Neck Cancers||Cancers that affect a person’s mouth, larynx, oesophagus or throat can impact on their ability to speak. Brain tumors can affect how a person can attend and process language.|
|Cleft lip and palate||Children can be born with a variety of cleft types and with variable severity. In a cleft lip there is a separation of the sides of the upper lip. A cleft palate is an opening in the roof of the mouth in which the two sides of the palate did not join while your baby was developing in utero. Most clefts are surgically repaired. Speech may or may not be affected.|
|Hearing Loss||There are different types of hearing loss that can make it difficult or impossible for a person to hear what someone is saying and sometimes their own speech may not be easily understood. Many people wear hearing aids and want speakers to do things that make it easier for them to hear and understand what is being said. However, if a person is Deaf and uses sign language, they require sign language interpreting services, not the services of a communication intermediary.|
|Learning Disability||People with learning disabilities have challenges with reading, spelling, and/or writing. In addition, many people with learning disabilities have difficulty expressing their messages in a clear manner, understanding questions and following directions, reading and comprehending material.|
|Attention Deficit / Hyperactivity Disorder (ADHD)||ADHD is a condition of the brain that affects a person’s ability to pay attention. A person with ADHD may have difficulty staying in one place, and may be restless and agitated. They may have difficulty concentrating, staying focused, planning, organizing, completing tasks, and learning new things. They may be impulsive and have difficulty thinking before acting.|
|Voice Disorders||There are different types of voice disorders that can result in a weak voice that makes it difficult for a person to speak loudly or be understood. Some disorders result in hoarseness, breathiness,quivering, jerkiness, or a rough sounding voice. Some people may be able to speak for a short period of time.|
|Multiple Sclerosis (MS)||MS is currently classified as an autoimmune disease of the central nervous system (brain, spinal cord). MS can cause symptoms such as extreme fatigue, lack of coordination, weakness, tingling, impaired sensation, vision problems, bladder problems, cognitive impairment and mood changes. Speech may be weak and unclear.|
|Parkinson’s Disease||Parkinson’s disease (PD) is a neurodegenerative brain disorder. People with Parkinson’s may have unclear, hoarse, quiet and monotonous speech. People may misinterpret an individual’s mood due to reduced facial expressions, altered hand gestures or changes in postures.|