I. THE NATURE OF BINAURAL HEARING Binocular vision gives a perception of distance through the coördination in the brain of sensations coming from the two retinas and the two sets of ocular muscles. In a somewhat comparable way, one determines whether a sound comes from the right or left side by the coordination of sensations coming from the ears. In other words, the lateral localization of sound1 is a result of binaural hearing. A clear understanding of two terms is essential for following a discussion of the subject, and these terms will be briefly explained. In figure 1, D represents the head of a listener seen from above. R and L are his right and left ears. B is the position of a sound. The segments of concentric circles represent sound waves. The listener, D, knows that the sound is on his right side, for two reasons. In the