Cortical processing of sound-source location

Lesion studies indicate that the auditory cortex is required for accurate sound localization in many species. However, we still have a poor understanding of how auditory spatial information is encoded in the cortex and of the relative contribution of different cortical areas to spatial hearing. Electrophysiological recordings from neurons in the primary auditory cortex (Al) have shown that their spatial selectivity is shaped by a combination of binaural interactions and spectral cues provided by the external ears. Neurons with similar binaural and spatial response properties appear to be arranged in clusters, although there is no conclusive evidence for any topographic order in spatial selectivity within the cortex. Recent studies using virtual acoustic space stimuli, which simulate over headphones all the localization cues associated with real sound sources, have shed light on the way in which those cues are processed by Al neurons and on the factors that influence the development of their spatial response properties. © S. Hirzel Verlag EAA.