Listening through different ears alters spatial response fields in ferret primary auditory cortex

The localization of sounds in space is based on spatial cues that arise fro m the acoustical properties of the head and external ears. Individual diffe rences in localization cue values result from variability in the shape and dimensions of these structures. We have mapped spatial response fields of h igh-frequency neurons in ferret primary auditory cortex using virtual sound sources based either on the animal's own ears or on the ears of other subj ects. For 73% of units, the response fields measured using the animals' own ears differed significantly in shape and/or position from those obtained u sing spatial cues from another ferret. The observed changes correlated with individual differences in the acoustics. These data are consistent with pr evious reports showing that humans localize less accurately when listening to virtual sounds from other individuals. Together these findings support t he notion that neural mechanisms underlying auditory space perception are c alibrated by experience to the properties of the individual.