Purpose: This study investigates the perceptual and acoustic correlates of gender in prepubertal voices. The study is part of a longitudinal project analyzing recordings of circa 60 German primary school children from the first to fourth grades (6- to 10-year-olds).
Method: Spontaneous and content-controlled audio recordings were made of 62 first-grade children (29 girls, 33 boys; age: 6- to 7-year-olds) from two German primary schools. Information on gender conformity was also recorded. A total of 167 listeners judged the gender of the voices on a 7-point scale. The results of the listening experiments and gender conformity ratings were related to a range of typical acoustic parameters.
Results: Measures of self-reported gender conformity differ significantly between the boys and the girls. Sixteen of the 62 children show unambiguous gender attributions in the listening experiment. A hierarchical cluster analysis including gender perception, gender conformity, and acoustic parameters shows four different types of speakers. Two multiple regression models revealed a significant main effect of fundamental frequency on the gender perception ratings of the listening experiment across and within gender. Significant correlations were found between the center of gravity and skewness of the sibilants and gender conformity, especially for the male speakers.
Conclusions: Fundamental frequency plays an important role in influencing perceptual judgments, whereas sibilant spectra are correlated with gender conformity. In further listening experiments, we will examine in more detail the role of individual acoustic parameters and analyze how the vocal expression of gender and gender conformity in individual children develops before reaching puberty.