Developmental trends in vocal fundamental frequency of young children.

Fundamental frequency (F0) values are reported for 14 children between the ages of 11 and 25 months, an age period characterized by changes in physiological and linguistic development. Subjects were grouped into 3-month age intervals reflecting a continuum of physical development and were audiotape-recorded during spontaneous speech productions. Acoustic analysis of average F0 and F0 variability was performed. F0 variability was found to decrease as subject age increased, as did segment durations. The decrease in average F0 across the arbitrary age groups did not reach significance; however, when viewed within the overall developmental period and in comparison with data from other studies of younger and older children, average F0 during this age is consistent with a decreasing trend throughout early childhood.