Psycholinguistic assessment of developmental speech disorders

Although various psycholinguistic models of speech and language processing have been developed to account for levels of breakdown in developmental speech disorders, it is not obvious how they are to be applied in clinical practice. At the same time, speech and language therapists have routinely been using a wide range of procedures, including published tests, that tap different levels of phonological processing in the child. When analysed and classified appropriately, these procedures can form the basis for a comprehensive psycholinguistic investigation of developmental speech disorders. The aim of this paper is to present a clinically usable, needs-driven but theoretically motivated framework for investigation. The framework is organised in terms of a series of questions that the clinician can pose about the levels of deficit in processing that may be giving rise to the child's speech problems. It is illustrated by means of a case study of a child with a severe developmental speech disorder, which reveals a complex pattern of deficits within the speech processing chain. As the main purpose of the framework is to provide a useful clinical tool to facilitate the planning of appropriate therapy for the individual child, some therapy objectives deriving from the assessment are outlined.