Speech sound disorder is a communication disorder in which children have persistent difficulty saying words or sounds correctly. Speech sound production describes the clear articulation of the phonemes (individual sounds) that make up spoken words. Speech sound production requires both the phonological knowledge of speech sounds and the ability to coordinate the jaw, tongue, and lips with breathing and vocalizing in order to produce speech sounds. Children with speech sound disorder may have difficulty with the phonological knowledge of speech sounds or the ability to coordinate the movements necessary for speech. These communication difficulties can result in a limited ability to effectively participate in social, academic, or occupational environments.
The DSM-5 includes the following diagnostic criteria for Speech Sound Disorder:
- Persistent difficulty with the production of speech sounds that interferes with the intelligibility of one's speech or prevents verbal communication
- Limitations on communication interfere with social participation or performance at school or work
- The symptoms begin early in life and are not attributable to other medical or neurological conditions
In typically developing children, approximately half of speech should be intelligible by age 2 and most speech should be intelligible by age 4.
According to the Child Mind Institute, some other potential signs of a speech sound disorder include:
- Leaving out sounds or substituting an incorrect sound for a correct one
- A quality of voice (e.g., atypically hoarse or nasal) or sudden changes in pitch or loudness that make understanding speech more difficult
- Running out of air while talking
The cause of speech sound disorder is not well understood in many cases. Children who develop speech sound disorder often have family members with a history of speech or language disorder, indicating a genetic component of this condition.
Treatment for speech sound disorder primarily consists of speech and language therapy. A speech-language pathologist can develop a treatment plan that helps children identify and correct the sounds or words they have difficulty saying. The speech-language pathologist can show the child how to move their tongue and lips to produce sounds correctly and provide opportunities to practice these skills.
In most cases, children with speech sound disorder respond well to treatment and speech difficulties improve over time. When a language disorder is also present, however, the speech disorder has a poorer prognosis and may be associated with specific learning disorders.