Bruce L. Smith Mary Kay Kenney
Dept. of Commun. Sci. and Disord., Northwestern Univ., 2299 Campus Dr. N, Evanston, IL 60208
Although several previous studies of normally developing children have examined effects of speaking rate changes on segment duration and variability and their possible relationship to neuromotoric maturity for speech, there have been no investigations concerned with children's ability to directly control the variability of their speech. The present study attempted to evaluate children's control of temporal variability by assessing the performance of 7- to 11-year-old subjects who were asked to minimize variability in their speech. The tasks included: (1) a control condition, in which 11 subjects repeated a variety of stimuli 25 times each, with no special instructions as to how they were supposed to produce them, and (2) an experimental task, in which subjects were specifically instructed to be as consistent as possible in repeating stimuli in an attempt to minimize variability. Results indicate that for the group as a whole, the temporal variability of various speech segments did not tend to differ substantially when comparing the children's control and experimental productions, with approximately half the subjects showing small decreases in variability and half showing small increases for the segments that were measured. It, thus, appears that for at least this type of repetition task, subjects perform at essentially optimal levels, in terms of variability, even when not specifically attempting to do so.