Accelerated speech in dysarthria after acquired brain injury: acoustic correlates.

Abstract

ABSTRACTThe present study reports on some acoustic dimensions of perceptually accelerated speech in dysarthria. Twelve dysarthric patients who were clinically judged as presenting an increased speech rate were investigated. Control groups of slowed dysarthrics (n = 12) and of normal subjects (n = 15) were also examined. The speech material consisted of chains of plosive‐vowel syllables uttered in a sentence repetition task. The speech wave envelope of these sentences was evaluated with respect to characteristic temporal and amplitude patterns. Proportions of stop gaps, noise segments and segments of quasiperiodic oscillation were also determined.The patients with accelerated speech had normal or near‐to‐normal syllabic rates. Segmental contrast was more or less reduced, depending on the degree of severity. Concerning the proportions of voiced and voiceless segments two different types of impairment could be discerned. Possible physiological interpretations of these results and the relation between acoustic and perceptual dimensions of speech tempo are discussed.