Articulatory, developmental, and gender effects on measures of fundamental frequency and jitter.

Fundamental frequency (Fo) and jitter were measured in digitized live-voice productions of sustained vowels [a], [i], and [u] from women, men, and 6- through 9-year-old children. Results showed (a) significant developmental differences for mean Fo and for the pattern of jitter by vowel type, (b) significant gender differences in Fo and jitter only for adults, (c) significant differences in Fo and jitter according to vowel type for all subjects, and (d) similar amounts of mean absolute jitter for children and women for all vowels with nonsignificantly different values of jitter for boys and men on [i] and [u] productions. Results are related to Honda's theory of intrinsic Fo for vowels and to Titze's neurologic model of jitter.