Effect of Interaural Difference for Localization of Spatially Segregated Sound

The role of interaural differences in localization of spatially segregated sound was clarified by performing listening tests on sound localization. Four subjects were asked to distinguish two sources of white noise with various interaural time differences (ITDs) or interaural level differences (ILDs). As a result, the segregated rate reached 80% when the ITD between two white noise sources corresponded to an angular difference of 22 degrees. The segregated rate degraded to 50% when the ITD between two white noise sources corresponded to an angular difference of 7 degrees. In addition, the segregated rate reached 80% when the ILD between two white noise sources corresponded to an angular difference of 30 degrees. The segregated rate degraded to 50% when the ILD between two white noise sources corresponded to an angular difference of about 15 degrees. These results suggest that sound sources could be spatially segregated using even only ITD or ILD.