Experimental manipulation of speaking rate for studying temporal variability in children's speech

Children's speech timing is often more variable than adults'. In the present study, two hypotheses that have been proposed to account for this observation are considered. One claims that children do not have neuromotor control capabilities comparable to adults. The other suggests that the greater variability is a statistical consequence of children's longer segment durations. These two hypotheses were examined by having children and adults speak at both faster and slower rates than normal. Within-group comparisons across different rates and between-group comparisons for similar durational values were made from spectrographic measurements. Results indicate that both statistical and neuromotor factors seem to contribute to the greater variability commonly observed in children's speech.