Upper median plane localization when head-related transfer functions of different target vertical angles are presented to the left and right ears

Abstract

Previous studies showed that the distortion of the spectral information by occluding the pinna cavities of one of the ears decreases the accuracy of vertical localization. However, it is unclear whether vertical localization can be accomplished using the spectral information at only a single ear or requires the spectral information at both ears. In the present study, median plane localization tests in which the head-related transfer functions (HRTFs) for different target vertical angles were presented to each ear of the subjects were carried out. The results showed that the subjects either localized a single sound image to the target vertical angle presented to either the left or right ear or localized two sound images to both target vertical angles, with approximately the same accuracy as when identical target vertical angles of HRTFs were presented to both ears. These results imply that the spectral information at only a single ear provides the spectral cue for vertical localization.