Spatially incongruent sounds affect visual localization in virtual environments

Distance underestimations along the depth plane are widely found in virtual environments. However, past findings have shown that changes in the visual aspects of virtual reality settings do not lead to more accurate depth estimates. Therefore, we examined if nonvisual stimuli, namely, sounds, could serve as cues that affect observers' depth perception. Accordingly, we conducted two distance discrimination tasks to examine whether observers' depth localization is affected by a spatially incongruent sound. In Experiment 1, a spatially incongruent sound made a visual target appear farther away than a visual target presented with no sound only when a far-distance range (i.e., longer than 12 m) was introduced. Experiment 2 further indicated that the sound shifted visual localization only when audiovisual spatial disparity did not exceed 4°. Taken together, our findings suggest that the depth localization of a visual object in virtual reality can be altered by a spatially incongruent sound, and provide a potential approach that we can adopt a spatially incongruent sound as a cue to reduce the depth compression in VR.