The Causes of Phonological Disability

Also referred to as articulation disorder, phonological disorder is the inability among children to produce all or some sounds necessary for speech normally associated with their age. Exhibited in various levels of severity -- from generally understood speech with some sounds slightly mispronounced to being completely incomprehensible even to parents and immediate family -- phonological disability may have adverse effects on the child's socialization process and school performance. The causes of phonological disability vary according to type.

Structural Problems for Producing Sound

• Also known as developmental articulation disorder, this type of phonological disability is one caused by problems in the shape and structure of bones and muscles used for producing sound such as the tongue, teeth, palate and the roof of the mouth. These problems make producing certain sounds difficult and in some cases entirely impossible. Surgical procedures for correcting these structural problems followed by speech therapy usually lead to corrected normal speech.

Neurological Problems

• Another type of phonological disability -- also known as dyspraxia or dysarthria -- is caused by neurological problems or certain abnormalities in the brain. Such abnormalities result to poor or insufficient fine motor control over the essential muscles that produce sounds. Cerebral palsy, among other disorders, is known to cause neurological problems leading to phonological disability.

Unknown Causes

• Developmental phonological disorder is the term often used to refer to the type of phonological disability of generally unknown cause or origin. This type of phonological disability is even manifested among individuals with normal hearing, of average intelligence and with no detectable anatomical, physiological or neurological deficit and even showing normal development in the expressive language domain. With a considerable percentage of phonological disability cases falling into this category, conclusive findings regarding the causes are yet to be arrived at.

Observations on Phonological Disability and Some Probable Causes

• Manifested in about 2 percent of 6 to 7-year-olds and in about 3 percent of preschoolers, phonological disorder has been observed to be more common among boys. The risk of developing the disorder is significantly higher among males, with siblings already having the disorder and those with poorly-educated mothers.

Other Factors

• Other factors that may contribute to developing phonological disability or may result to manifestations mistaken for symptoms of the disorder include poor hearing, poverty, having first language other than English, regional accents or pronunciations and poor or limited exposure to other sounds. As such, the child's background and history should be considered when diagnosing for phonological disability.