- Speech disorder is a condition where the individual has difficulty in sound production. Someone who has lost the ability to produce sound totally is considered mute. Speech disorders occur due to loss of the ability to use words in the relevant context.
Types of Speech Disorders
According to the American Speech-Language-Hearing Association (ASHA), following are the major types of speech disorders:
Spasmodic Dysphonia: This is the disorder where the muscles of the larynx or the voice box move involuntarily. It is basically of three types:
- Adductor spasmodic dysphonia: Here, the vocal cords close involuntarily, cutting off some words. This gives the impression of stammering.
- Abductor spasmodic dysphonia: Here, the vocal cords open involuntarily and result in a weak, whispery voice.
- Mixed spasmodic dysphonia: Here, the cords open and close involuntarily due to which the person appears to be stammering sometimes and speaking in a low airy voice at other times.
Aphasia: This occurs due to damage to the communication center in the brain. It is also called Dysphasia and affects each person differently. Problems arise in the use of language while talking, writing or listening. This is mostly a result of head injury, brain tumor, brain hemorrhage or stroke.
Stuttering: This is a disorder wherein the person repeats the first half of a word, or prolongs words and syllables (generally vowels) or gives involuntary pauses in between the words. It can be both developmental (that begins in childhood) or acquired (caused due to other disorders like Asperger's syndrome). Sometimes, the stuttering may also be related to anxiety, stress, low self-esteem or a childhood stigma.
Apraxia: Apraxia is also a result of an injury to the brain. The individuals affected by this disorder are unable to express themselves consistently and correctly. This speech disorder is of two types:
- Developmental apraxia: It occurs in children and is generally present from birth. The severity varies from one child to another.
- Acquired apraxia: It is present in adults and results from a physical injury to brain. It depends on the age of the individual and the extent of the injury.
Articulation Disorder: This type of speech disorder occurs when the person is unable to produce a particular sound. Generally there is a problem in pronouncing 's','r' and 'i'. It occurs due to weak muscles or less control over the tongue. Sometimes, it may be very difficult to understand the speech of people with articulation disorder. This speech disorder is of two types:
- Distortion: Here, the individual is unable to produce a sound and ends up distorting it.
- Addition: In this case, the individual produces an extra sound.
After a stroke, some people experience language deficits (aphasia) that significantly impair their ability to communicate
Patients with Broca's Aphasia are able to write, to read, to listen and understand people, and are able to talk - but not able to form many coherent words. The condition is the result of an injury to Broca's area, the patient's ability to control what their mouths are saying goes away. Some patients are able to manage about four words, but most lose their ability to say what they want. Occasionally, they even lose the ability to understand that they aren't saying what they mean to say. One of the most famous cases of this was a man who simply repeated "Tono tono tono tono tono," to every question asked him. Although he could comprehend everything, he couldn't make his mouth say the words he needed to respond.