Anatomy and Physiology of the Avian Binaural System

Azimuthal sound localization in the chicken

“…Within this group, the chicken ( Gallus gallus ) is a well suited representative of this avian group, since several aspects of its auditory system—such as the anatomy, physiology, evolution and development—have already been studied (for reviews: [ 21 , 22 ]). Moreover, it has already been used as a model for the plesiomorphic condition of the avian auditory system and compared to the auditory-specialist barn owl [ 13 , 23 ]. Several studies were conducted in the chicken’s brainstem nuclei, showing, for instance, the neural processing of binaural cues, fundamental for sound source localization [ 24 , 25 ], and the role of the interaural canal in enhancing the interaural time difference (ITD) range [ 26 , 27 ].…”

“…Several experimental paradigms have been developed to measure the behavioral response to change in sound location, such as tracking saccadic head movements toward the target stimulus with the search coil technique [4,5], measuring the pupillary dilation response [6,7], and behavioral training in a Go/NoGo task [8]. Besides these experiments, other studies described the anatomical specializations which provide high auditory localization acuity (i.e., asymmetrical ears and facial ruff; [4,[9][10][11]), as well as the neuroanatomy and the physiological mechanisms underlying the computation and representation of auditory space in the brainstem (for a review: [12,13]). Consequently, some studies could accurately predict and explain aspects of the sound localization behavior of the barn owl according to the computation of the underlying neural substrates [14,15].…”