Quantification of motor speech abilities in stroke: Time-energy analyses of syllable and word repetition

Rapid syllable repetition (diadochokinesis or alternating movement rate) is routinely used in the assessment of dysarthria. This report presents diadochokinetic data for 28 subjects with stroke. Acoustic analyses were used to obtain quantitative information on several parameters, including syllable rates, means and variability for syllable duration and intersyllable gap duration, and acoustic energy present during the intended stop-gap interval. The group as a whole demonstrated slow and variable performance on the repetition task, with slowness being related to lengthening of both syllables and the intersyllable gaps. In addition, the subjects frequently exhibited voicing or noise energy (spirantization) during the intersyllable gap, including the intended stop gap. A quantitative analysis procedure is outlined for the acoustic description of rapid syllable repetition.