While some children may have difficulty with one or two sounds, other children have difficulty with a whole group of sounds that share similar characteristics. These are known as phonological processes. Phonological processes are a normal part of speech development however when these error patterns persist beyond developmental norms, a child is described as having a phonological process disorder.

Examples of phonological processes seen in very young children include:

The following demonstrates the general age ranges in which the correct production of these sounds should be acquired:

• Syllable deletion: the child leaves out the unstressed syllables in words e.g. says 'nana' for banana

• Final consonant deletion: the child leaves off the ending consonant in words e.g. says 'da' for dog.

• Reduplication of sounds or syllables: the child may say 'baba' for bottle or 'gog' for dog.

• By six to seven years: r,th

Many speech sound disorders occur without a known cause. A child may not learn how to produce sounds correctly or may not learn the rules of speech sounds on his or her own. These children may have a problem with speech development, which does not always mean that they will simply outgrow it by themselves. Many children do develop speech sounds over time but those who do not, often need the services of a Speech-Language Pathologist to learn correct speech sounds.

Children with a history of speech sound disorders are at risk for experiencing difficulty in their literacy development.