Abstract
The variability in comfortable effort level across experimental sessions as assessed by measures of speaking fundamental frequency (SFF) and vocal intensity (VI) has been reported for normal adult speakers. However, no such data are available for young children. The goal of this study was to determine the variability in SFF and VI seen in normally developing young children. Fifteen males and 14 females between the ages of 3 and 4 years were asked to repeat a vowel, a sentence, and four words at a comfortable speaking level on 3 separate days, each 1 week apart. SFF and VI were determined for each utterance. Statistical treatment of the data revealed that when combining all the data, there were no significant differences for mean SFF or VI across test sessions. However, the young females generally spoke with greater VI than young males. These results suggest that normal-speaking children at a very young age are, on the average, similar in the degree of variability to adults for SFF and VI across experimental sessions when asked to set their own level of output. These findings provide a baseline for the extent of variability in SFF and VI seen in normally developing young children.