Effects of Temporal Fine Structure on the Localization of Broadband Sounds: Potential Implications for the Design of Spatial Audio Displays

In the design of symbology for spatial audio displays, a great deal of emphasis has been placed on the importance of bandwidth for achieving robust localization accuracy. However, there are some cases where the temporal characteristics of a audio signal can have a large impact on its localizability. In this study, we examined localization accuracy for three different wideband stimuli: a broadband noise, a 100-Hz click train, and a 100-Hz click train with randomized phase. When the stimulus presentation level was low (40 dB SPL), localization performancewas reasonably good for all three stimuli. However, as the presentation level increased to 70 dB or higher, localization performance degraded dramatically for the click train stimulus but remained roughly constant for the other two stimuli. The results suggest that display designers must consider some factors other than bandwidth when they design the symbology for real-world spatial audio displays.