INTERSYLLABIC MOVEMENT TIMING IN THE FLUENT SPEECH OF STUTTERERS WITHDIFFERENT DISFLUENCY LEVELS

The goal of this study was to identify possible differences in movemen t timing in the fluent speech of adult stutterers who show varying lev els of speech disfluency. Strain gauge recordings of lip and jaw movem ents and electroglottographic recordings of laryngeal vibration were o btained in 31 subjects as they repeated simple speech utterances. Meas ures of the duration and variability of intersyllablic articulatory ev ents were analyzed in relation to speech disfluency level and history of speech treatment. As expected, movement durations were longer in su bjects who had been through speech treatment. No significant associati ons were observed between timing durations and disfluency level. Howev er, more disfluent subjects tended to show reduced variability in timi ng durations, an effect that was independent of speech treatment. This finding is interpreted in relation to previous observations on contro l systems that show instability and disfunction in association with re duced output variability. When disfluency level was measured during ph ysiologic testing, duration interacted with speech treatment, with mor e disfluent subjects in the treatment group showing increased duration s in their fluent speech. This effect is attributed to volitional cont rol intended to facilitate speech fluency.