Sociality Predicts Enhanced Auditory Thresholds and Binaural Hearing Processing Across Rodent Species

Sociality has evolved repeatedly in rodents, yet whether sociality has shaped auditory processing remains unclear. Here, we used auditory brainstem responses (ABRs) to examine the relationship between sociality and auditory processing in nine wild-caught rodent species that are not closely related evolutionarily. Phylogenetic comparative analyses revealed that sociality is correlated with enhanced auditory processing: social species (both monogamous and group-living) generally exhibited lower auditory thresholds for tone and click stimuli than solitary species. Group-living species also showed faster normalized latencies and higher relative amplitudes of the binaural interaction component (BIC) across tested interaural time differences (ITDs) than solitary species. In contrast, we found no differences in monaural ABR interpeak latencies or amplitude ratios of ABR waves I and IV among social groups with increasing sound intensities. Together, these findings indicate that sociality is associated with heightened auditory sensitivity in rodents and suggest that the evolution of complex social behavior may have favored enhanced auditory systems that facilitate effective social communication.