TOWARDS A STANDARDIZED ASSESSMENT PROCEDURE FOR DEVELOPMENTAL APRAXIAOF SPEECH

This study addresses the assessment of developmental apraxia of speech (DAS) in children. For this, 11 children with a clear diagnosis of DA S were selected, based on documented speech history and perceptual eva luation of speech. The children with DAS, as well as II normal-speakin g children, produced singleton real word and nonsense word imitations elicited in a standardised way. Phonetic transcriptions were analysed and errors in consonants classified. The results showed, firstly, that the children with DAS produced similar types of consonant errors as h as been reported in the literature, which corroborates the method of e licitation as a valid procedure to assess relevant speech symptoms of DAS. Secondly, a large quantitative difference between children with D AS and normal-speaking children was found, in that children with DAS p roduced an overall higher rare of singleton consonant errors (substitu tions, omissions, distortions) and cluster errors (cluster reductions) than the normal-speaking children. For the DAS group, the substitutio n-rate, particularly in real words (as opposed to nonsense words), was significantly correlated with severity as rated by two speech and lan guage pathologists. This suggests that substitution-rate yields an ade quate measure of severity of DAS. Thirdly, a qualitative difference be tween both subject groups emerged. Children with DAS did not benefit f rom the lexical status of the utterance (real versus nonsense word) to the same extent as normal-speaking children. Based on these findings the nature of the underlying deficits in speech production in DAS is d iscussed.