Variability in the initiation of articulatory movements in the speech of stutterers and normal speakers

This study was designed to investigate the differences between stutterers and normal speakers in phonatory and articulatory timing during the initiation of fluent utterances of monosyllabic words. Electromyographic recordings of four articulatory muscles and recordings of glottal vibrations were made of repetitive utterances of a series of monosyllabic words by 15 stutterers and 17 nonstutterers. These data were analyzed in terms of average interval times between voice onset and onset of EMG activity and between onset of EMG activity in each articulator and in terms of the intrasubject variability of these durational measures. Results showed that there were no significant differences between stutterers and nonstutterers in average interval times and that stutterers, in general, were significantly more variable in their speech onset timing. Findings are discussed in terms of recent hypotheses concerning the role of timing disturbances as the main source of speech disruption in stutterers.