Binaural disparity cues in median-plane localization.

Several investigators have discussed the problem whether median-plane localization needs binaural disparity cues or not. In order to make it clear, two localization tests are carried out with the localization simulation system using a digital computer. In each test, sound stimuli include either only spectral cues or only binaural disparity cues, and they are presented to subjects in binaural condition. The results show that the localization accuracies are almost the same regardless of the presence of binaural disparity cues, and that most sound images produced by only binaural disparity cues appear at a certain biased direction. Consequently, it is concluded that binaural disparity cues alone cannot accomplish median-plane localization.