Anatomy and Physiology of the Avian Binaural System

This chapter reviews the anatomical structures and physiological processes that underlie the perceptual effects of binaural hearing. Although the focus is on avian systems, pioneering work in humans and other mammals are also included to provide context. A description of the acoustics of the binaural hearing and processing of the monaural acoustic cues in the cochlear nuclei is presented first. The mechanisms by which the monaural signals from the left and right are compared and combined across frequencies to generate neurons in the inferior colliculus with circumscribed spatial receptive fields are then described. Finally, the role of the spatially selective cells in auditory perception in acoustical environments with echoes and multiple sound sources are examined and discussed.