Vocal characteristics in pre-adolescent and adolescent children: a longitudinal study

A number of cross-sectional studies have been reported for the fundamental frequency and formant frequency data in the voices of a group of 20 pre-adolescent children aged between 6 and 10 years (Whiteside, S P, Hodgson, C. Acoustic characteristics in 6-10-year old children's voices: some preliminary findings, Log Phon Vocol 1999; 24: 6-13, Whiteside, SP, Hodgson, C. Some acoustic characteristics in the voices of 6-10-year-old children and adults: a comparative sex and developmental perspective, Log Phon Vocol 2000; 25: 122-132). About 15 of the children who participated in these earlier studies, participated in a follow-up study approximately 42 months later. Their speech data were recorded and analysed acoustically to investigate longitudinal patterns of development in their voices by examining data for fundamental frequency and the first three formant frequencies of a phrase final vowel. Data obtained from this follow-up study (Time 2) were compared with earlier corresponding data (Time 1). The findings of this study indicated that there was evidence for maturation in the voice parameters of all subjects between Time 1 and 2, with changes being observed for the majority of comparisons for parameters, across age and sex. In addition there was also evidence of individual differences in the maturational patterns which were observed. These individual differences highlight the degree of variation which occurs in the developmental changes of voice characteristics.