Md. Mcclean et al., INTERSYLLABIC MOVEMENT TIMING IN THE FLUENT SPEECH OF STUTTERERS WITHDIFFERENT DISFLUENCY LEVELS, Journal of speech and hearing research, 37(5), 1994, pp. 1060-1066
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.