Children typically development speech sounds over time and each sound is expected to develop within a specific age range. A speech sound disorder occurs when a sound does not develop within the expected age range. Speech sound disorders include problems with articulation (making sounds) and phonological processes (sound patterns).
An articulation disorder involves problems making speech sounds. Sounds can be substituted, left off, added or changed. These errors may make it hard for people to understand you.
- Young children often make speech errors. For instance, many young children sound like they are making a “w” sound for an “l” sound (e.g., “wewwow” for “yellow”) or may leave sounds out of words, such as “mah-key” for “monkey.” The child may have an articulation disorder if these errors continue past the expected age.
A phonological process disorder involves patterns of sound errors. For example, substituting all sounds made in the back of the mouth like “k” and “g” for those in the front of the mouth like “t” and “d” (e.g., saying “tup” for “cup” or “das” for “gas”).
- Another rule of speech is that some words start with two consonants, such as broken or spoon. When children don’t follow this rule and say only one of the sounds (“boken” for broken or “poon” for spoon), it is more difficult for the listener to understand the child. While it is common for young children learning speech to leave one of the sounds out of the word, it is not expected as a child gets older. If a child continues to demonstrate such cluster reduction, he or she may have a phonological process disorder.