Developmental verbal dyspraxia II: A developmental perspective on two case studies*

Abstract
A longitudinal study of the speech errors of two school-age children with what was described as developmental verbal dyspraxia is presented. By comparing them with a group of normally developing children matched on articulation age, it was possible to identify speech errors not typical of earlier speech development, involving problems with syllable structure planning and vocal tract coordination. The speech-disordered children could produce more words correctly than the controls, but, when they did make speech errors, these were more serious than those found in the younger children. The speech-disordered children were followed up 4 years later. Although their speech had improved, they presented with the same profile of error types. They had increased intelligibility by adding more word-specific articulations but still had difficulties with novel and complex material. The adoption of a developmental framework in this study allowed the identification of different levels of breakdown within the speech production process. The case-study method is recommended to investigate how these levels may interact and the clinical implications of the findings are outlined.