Basics of Developmental Disorders of Speech and Language

The development of speech and language from infancy to around 4 years of age is a central issue and thus a useful indicator of a child’s overall development. Any impairment in this critical period may negatively affect the child’s future development and affect the verbal cognitive development, the individual’s ability to communicate, school attainment, psychosocial development, vocal well-being and quality of life. Learning language depends on learning grammar (a knowledge- and rule-based system); learning speech depends on learning which sounds are used in a language, involving sound production, perception and organization. Regular speech-language development in monolingual children proceeds in stages with regularities with respect to time and content. Knowledge of these milestones of the typical language development seen in context with cognitive, auditory, motoric, psycho-emotional and general development of a child is a prerequisite to recognizing developmental language delays or disorders. Developmental disorders of speech and language (DDSL) are common diseases. Prevalence numbers are mostly reported from 6 to 8%. They affect boys twice as frequently as girls and all languages a child speaks. For their diagnosis they have to be differentiated from other disorders or functional abnormalities, which may mimic DDSL symptoms, as well as from sociogenically caused language abnormalities.