Quantitative assessment of dysarthria and developmental apraxia of speech

For a particular child, a multiplicity of factors may underlie defective articulation. In order to assess the degree of involvement of neuromotor, phonological and developmental factors, procedures to obtain quantitative measures of motoric and phonemic involvement in dysarthria and developmenal apraxia of speech (DAS) are presented. The test procedures used were Maximum Performance Tasks (MPTs), and Word-and Nonword imitation tasks. The analysis techniques consisted of acoustic analyses, and broad phonetic transcription followed by automatic analyses of error types. The results showed, that dysarthria is mainly characterized by slowness and by a high proportion of distortions. DAS is characterized by a high error rate, sequencing problems, and many errors of place-of-articulation; there are striking qualitative correspondences with speech errors ('slips of the tongue') in the speech of normally speaking children. Comparison of these disorders suggests that children with defective articulatory development show individual degrees of dysarthric and dyspraxic involvement.