A longitudinal study of the development of stop consonant production in normal and Down's syndrome children.

In order to compare phonological development in normal and Down's syndrome children, longitudinal observations were made of four normal children from 18 to 36 months of age and five Down's syndrome children from 3 to 6 years of age. Singleton stops and stop clusters were analyzed to determine if the Down's syndrome children evidenced phonological processes and other sound patterns similar to those of the normal children. Although quite similar patterns were observed for the two groups, the Down's syndrome children showed considerable delay in comparison to the normally developing children.