Types of Speech Disorders

Speech disorder or dysphonia is a condition where the individual has difficulty in producing sound. 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.

Many times, the cause for the problem remains unknown. Some of the known causes include:

» Mental illness
» Brain injury
» Neurological speech disorders
» Alcohol abuse or drug abuse
» Genetic disorders
» Vocal abuse/misuse
» Hearing loss
» Autism

According to the American Speech-Language-Hearing Association (ASHA), following are the major types of speech disorders:

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.

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.

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 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.

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.

It is generally seen in children. Speech sound disorders may occur due to any developmental disorder like autism or Down syndrome and also due to physiological or neurological problems.

 It is of the following four types:

• Omissions: The child leaves a particular sound because he either cannot produce it at all, cannot produce it correctly or cannot use it properly.
• Additions: This occurs when an extra sound is added to a word.

• Distortions: Here, the actual sound of the syllable is distorted and an inexplicable sound is produced.
• Substitution: This occurs when the child consistently substitutes one sound with another.

Cluttering speech disorder affects the fluency of speech. It occurs because the person speaks very fast or repeats things many a time to make it comprehensible. There is no distinct cause for cluttering. It may occur due to drug abuse or prolonged illness.

It is commonly known as slurred speech. The speech is slow or inaccurate. It is generally caused by stroke, multiple sclerosis or brain tumor. This leaves the muscles in the mouth or tongue weak or paralyzed and it becomes difficult to control them.

It is also callled stigmatism, and occurs when one can't produce a specific speech sound. It is of 3 types:

• Interdental: Occurs when the tongue comes in between the teeth at the time of speech.
• Lateral: A wet sound is produced because air escapes from the sides of the tongue.
• Palatal: Happens when the mid section of the tongue touches the soft palate.

It is a rare speech disorder. Here, the rhythm, modulation, timing and intensity of speech is disrupted. Sometimes also referred to as foreign accent syndrome, its causes have not been fully understood. It may be a result of Parkinson's disease, tumor or stroke that affects the brain.

It is a language or communication speech disorder where the individual has difficulty in verbally expressing himself. Generally, comprehension of language is better than its expression in such cases. The person fumbles for using correct grammar, tenses, structure, vocabulary, etc., and the speech becomes hesitant.

This speech disorder is of two types:

• Developmental: This is seen in children. There is no specific cause for this disorder and is believed to affect boys more than girls.
• Acquired: It is acquired by an individual post stroke or head injury in adulthood.

The individuals face difficulty in using language while speaking, writing or reading. It affects everyone differently. Some find it hard to communicate verbally and others are unable to express themselves clearly. This usually involves difficulty in learning numbers or maths. Trouble in telling left from right or difficulty in telling time is also observed.

In this type of speech disorder, the individual is physically unable to produce certain sounds like 'c' or 't' with the use of tongue, teeth, lips, palate or the facial muscles and nerves. They always produce an incorrect sound as a substitute.

Most of these speech disorders can be cured by speech therapy. A speech and language pathologist should be contacted to find out the type of disorder that has affected an individual and its possible causes. Some individuals also benefit from their sessions with an audiologist. Regular sessions and practice is also very helpful.

Those with physical impairment may be helped by surgery. Hearing and speech disorders are closely related. Unless one hears correctly, he can't produce sounds. Some disorders are pragmatic speech disorders, i.e., they are acquired due to bad practical experiences like verbal abuse, physical or mental trauma or some shock that might lead to fear of speech.

Whatever the reason may be, a speech disorder leaves the individual with low confidence and morale. Although, it can be treated with therapy, one should always bear in mind that the love and support from friends and family is always required. Speech disorders are not incurable. All that is required is dedicated effort in the proper direction.

Disclaimer: The information provided here is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.