Speech delays occur in about 10% of children in the U.S. The cause is often unknown but some of causes are related to hearing loss, cognitive impairments, neuromuscular disorders, viral disease, physical impairments such as cleft lip or palate and / or inadequate speech and language models.
Parents are usually the first to notice that their child is not developing language skills at the same rate as other children and will describe their child as ‘not talking,’ ‘a late talker,’ to their doctor.
It is important to keep in mind that language development involves more than just speech, it also includes other forms or communication, such as sign language, writing, and visual skills (pointing, etc.). Delayed language is characterized by a marked slowness in the development of the vocabulary and grammar necessary for expressing and understanding thoughts and ideas. About 5-10% of children have a developmental disability that causes a delay in their speech and language development.