While high-level adaptation to faces has been extensively investigated, research on behavioural and neural correlates of auditory adaptation to paralinguistic social information in voices has been largely neglected. Here we replicate novel findings that adaptation to voice gender causes systematic contrastive aftereffects such that repeated exposure to female voice adaptors causes a subsequent test voice to be perceived as more male (and vice versa), even minutes after adaptation [S.R. Schweinberger et al., (2008), Current Biology, 18, 684-688). In addition, we recorded event-related potentials to test-voices morphed along a gender continuum. An attenuation in frontocentral N1-P2 amplitudes was seen when a test voice was preceded by gender-congruent voice adaptors. Additionally, similar amplitude attenuations were seen in a late parietal positive component (P3, 300-700 ms). These findings suggest that contrastive coding of voice gender takes place within the first few hundred milliseconds from voice onset, and is implemented by neurons in auditory areas that are specialised for detecting male and female voice quality.