A Study on individualization of Head-Related Transfer Function in the median plane

Individualization of Head-Related Transfer Function (HRTF) is important. If an inappropriate HRTF is used, wrong sound localization and less sense of presence occur. In this paper, we studied the admissible ranges for P1, N1 and N2, which is spectral cue of the median plane for the sound localization. In order to verify the validness of the admissible ranges for the P1, N1 and N2, we investigated individualization differences in the P1, N1 and N2. As a result, we found less individualization difference on the P1, and big individualization difference in N1 and N2. And, we carried out the listening experiments on these findings. We revealed that P1 and N1 should be accurate; admissible range is narrow, and N2 is not strict, strict tuning of N2 is not required. Moreover, we observed the selected HRTFs in which variations of N1 and N2 according to the change of elevation. The result suggested that the control of P1 and N1 is especially important. This indicated necessity of adapting slope of the N1 and N2 when human perceive the change of elevation