ABSTRACT
This chapter gives an overview of research aiming to determine at which levels of speech production the deficits of children with developmental apraxia of speech might be located. We conclude that two levels might be involved in developmental apraxia of speech, namely syllable planning (including the syllabary) and motor programming. Next, the results of two experiments are discussed, each focussing on one of these two levels. The first experiment, in which the syllable structure was manipulated, demonstrated no systematic durational patterns in children with developmental apraxia of speech, a result that is interpreted as signifying a deficit in syllable planning, specifically in using prosodic parameters in articulation. The second experiment showed a deviant effect of a bite-block in children with developmental apraxia of speech as compared to normally speaking children, which supported the interpretation of a motor programming deficit in developmental apraxia of speech. Our conclusion is that in developmental apraxia of speech both syllable planning and motor programming are involved. Insufficient durational control plays a central role at both of these levels.
