The Effect of Fundamental Frequency on Gender Perception in Prepubertal Children: Insights from the LoKiS Database

This study examines the impact of fundamental frequency on gender perception in prepubertal children in the LoKiS database - a longitudinal project collecting and analyzing recordings of approximately 60 German primary school children aged 6 to 10years. Spontaneous and content-controlled audio recordings were collected in two German primary schools. Three distinct listening experiments with over 100 listeners were conducted. In the first experiment, listeners judged the gender of the voices on a seven-point scale. The second experiment explored the relationships between perceptual attribute ratings and corresponding acoustic parameters associated with fundamental frequency. The third experiment utilized voice morphing techniques to investigate the influence of fundamental frequency on gender perception while controlling for other acoustic parameters. About one-third of the children receive unambiguous gender attributions. The perceived gender difference between children assigned female at birth (AFAB) and assigned male at birth (AMAB) increases from first to third grade. The feminine-sounding children were perceived as significantly higher-pitched and more melodious. A strong correlation between perceived pitch and measured fundamental frequency was found. While the acoustic analysis revealed only a few significant differences between AFAB and AMAB children in general, the feminine-sounding children exhibited markedly higher values than the masculine-sounding ones. Stronger differences of fundamental frequency and semitone range occur as AFAB and AMAB children get older. Linear mixed models confirm a significant influence of fundamental frequency and semitone range on gender perception. Other interacting factors include the speech material used, as well as the gender of the listener. The influence of fundamental frequency was even more pronounced when controlling for other acoustic parameters.