Fundamental frequency, jitter, and shimmer in preschoolers who stutter.

This investigation examined acoustic correlates of phonatory control in the speech of 10 preschool-aged boys who were stutterers (mean age = 45 months) recorded relatively close to the time of stuttering onset and in the speech of 10 boys who were nonstutterers (mean age = 46 months). For each subject, acoustic measurements of fundamental frequency, jitter, and shimmer were extracted from the 100 msec midportion of 30 vowels selected from fluent utterances in spontaneous speech. Significant differences between the two groups for shimmer measures are among the few positive findings in recent publications concerning the fluent speech of children who stutter.