Sex differences in subcortical auditory processing emerge across development

Human subcortical auditory processing is sexually dimorphic. The prevailing view – that sex differences arise from cochlear differences – remains unproven, and the extent to which these differences reflect distinct auditory processes is unknown. To determine the origin of subcortical sex differences, we mapped their emergence onto the peripheral-to-central maturation of the auditory system in 516 participants (250 female) across three age groups: 3–5, 14–15, and 22–26 years. To examine whether these sex differences arise from distinct processes, we compared developmental trajectories of each evoked-response component and tested their ability to predict a participant's sex and age. We find that some subcortical sex differences emerge well after the cochlea is mature and that each measure uniquely contributes to predicting participant demographics, indicating that sex differences arise from multiple central auditory processes.