The cause of phonological disorder in children is often unknown. Close relatives may have had speech and language problems. Other risk factors may include poverty and coming from a large family.
Phonological disorders may also be caused by:
Problems or changes in the structure or shape of the muscles and bones that are used to make speech sounds. These changes may include cleft palate and problems with the teeth.
Damage to parts of the brain or the nerves that control how the muscles and other structures work to create speech (such as from cerebral palsy).
Most children have problems pronouncing words early on while their speech is developing.
But by age 3, at least half of what a child says should be understood (intelligible) by a stranger.
By age 5, a child's speech should be mostly intelligible.
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.
Some of the more difficult sounds may not be completely correct, even by age 7 or 8.
Children with phonological disorder will substitute, leave off, or change sounds. 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.
Commonly, children with this disorder have:
Problems with words that begin with two consonants. "Friend" becomes "fiend" and "spoon" becomes "soon."
Problems with words that have a certain sound, such as words with "k," "g," or "r." The child may either leave out these sounds, not pronounce them clearly, or use a different sound in their place. (Examples include: "boo" for "book," "wabbit" for "rabbit," "nana" for "banana," "wed" for "red," and making the "s" sound with a whistle.)
Exams and Tests
Children should be examined for disorders such as:
The health care provider should ask about issues, such as whether more than one language or a certain dialect is spoken at home.
Milder forms of this disorder may disappear on their own by around age 6.
Speech therapy may be helpful for more severe symptoms or speech problems that do not get better. Therapy may help the child create the sound, for example by showing where to place the tongue or how to form the lips when making a sound.
The outcome depends on the age at which the disorder started, and how severe it is. Many children eventually 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 difficulty being understood by people outside the immediate family. Problems with social interaction and academic performance may occur as a result.
When to Contact a Medical Professional
Call your health care 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 are making him or her worried or embarrassed at any age
Friedman O, Wang TD, Milczuk. Cleft lip and palate. In: Flint PW, Haughey BH, Lund VJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, PA: Saunders Elsevier; 2010:chap 186.
Simms MD, Schum RL. Language development and communication disorders, In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 32.
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.