Phonological disorder is a type of speech sound disorder. Speech sound disorders are the inability to correctly form the sounds of words. Speech sound disorders also include articulation disorder, disfluency, and voice disorders.
Children with phonological disorder do not use some or all of the speech sounds to form words as expected for a child their age.
This disorder is more common in boys.
The cause of phonological disorders in children is often unknown. Close relatives may have had speech and language problems.
In a child developing normal speech patterns:
- By age 3, at least one half of what a child says should be understood by a stranger.
- The child should make most sounds correctly by age 4 or 5, except for a few sounds such as l, s, r, v, z, ch, sh, and th.
- Harder sounds may not be completely correct until age 7 or 8.
It is normal for young children to make speech errors as their language develops.
Children with a phonological disorder keep using incorrect speech patterns past the age they should have stopped using them.
Incorrect speech rules or patterns include dropping the first or last sound of each word or replacing certain sounds for others.
Children may leave out a sound even though they are able to pronounce the same sound when it occurs in other words or in nonsensical syllables. For example, a child who drops last consonants may say "boo" for "book" and "pi" for "pig", but may have no problem saying words like "key" or "go".
These errors may make it hard for other people to understand the child. Only family members may be able to understand a child who has a more severe phonological speech disorder.
Exams and Tests
A speech language pathologist can diagnose a phonological disorder. They may ask the child to say certain words and then use a test such as the Arizona-4 (Arizona Articulation and Phonology Scale, 4th revision).
Children should be examined to help rule out disorders not linked with phonological disorders. These include:
- Cognitive problems (such as intellectual disability)
- Hearing impairment
- Neurological conditions (such as cerebral palsy)
- Physical problems (such as cleft palate)
The health care provider should ask questions, such as if more than one language or a certain dialect is spoken at home.
Milder forms of this disorder may go away on their own by around age 6.
Speech therapy may help more severe symptoms or speech problems that don't get better. Therapy may help the child create the sound. For example, a therapist can show where to place the tongue or how to form the lips when making a sound.
The outcome depends on the age the disorder started and how severe it is. Many children will go on to develop almost normal speech.
In severe cases, the child may have problems being understood even by family members. In milder forms, the child may have trouble being understood by people outside the family. Social and academic problems (reading or writing disability) may occur as a result.
When to Contact a Medical Professional
Call your provider if your child is:
- Still difficult to understand by age 4
- Still unable to make certain sounds by age 6
- Leaving out, changing, or substituting certain sounds at age 7
- Having speech problems that cause embarrassment
Developmental phonological disorder; Speech sound disorder; Speech disorder - phonological
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Review Date 6/7/2022
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.