Auditory Localization: Physiology

The ability to locate the source of a sound is a fundamental property of normal hearing. Compared with the visual system, however, for which a relatively complete understanding of spatial processing has been achieved, at least with respect to the two-dimensional representation of visual space projected on the back of the retina, the study of neural coding of auditory space constitutes an altogether more complex problem. This is partly because the hearing organ of the inner ear—the cochlea—is arranged to represent the frequency of a sound, rather than the location of its source. This frequency tuning is known as tonotopy, with the highest frequency (pitch) sounds represented at the base of the coiled cochlea and the lowest at the apical end. Brain centers dedicated to ...