Comparison of spatial characteristics of head-related transfer functions between the horizontal and median planes

摘要

Head-related transfer functions (HRTFs) vary with source direction and thus contain major localization cues. In this work, the directional variation of HRTFs in the horizontal and median planes are studied using directional Fourier expansion. Results indicate that, up to 20 kHz, the preceding 8 or 9 order elevation harmonics account for 99% variation of HRTFs in the median plane; while the preceding 31 or 32 order azimuthal harmonics account for 99% variation of HRTFs in the horizontal plane. Therefore, the horizontal-plane variation of HRTFs is more complicated in comparison to the median-plane variation. Moreover, the front-back spatial symmetry calculated from expansion weights is compared between the horizontal and median planes.