Effect of individualization of interaural time/level differences with non-individualized head-related transfer functions on sound localization

Abstract

Head-related transfer functions (HRTFs) are known to include comprehensive auditory cues for sound source positions and show large inter-subject variation. Therefore, individualization of HRTFs is important for highly accurate sound localization systems such as virtual auditory displays. In the present study, we assume that the interaural time deffierence (ITD) and the interaural level difference (ILD) can be estimated from the listener’s anthropometric parameters. The individualization of the HRTFs is achieved by replacing the ITDs and ILDs of the non-individualized HRTFs with the listener’s ones. In this report, the effect of the individualization was evaluated by listening experiment. The non-individual HRTFs were obtained by interpolating magnitude response of the listener’s own HRTF and the flat ones. The ratios of the interpolation corresponded to the degrees of individuality. Then, the ITDs and ILDs were added to individualize HRTFs. From the results, the effect of the degree of individuality was insignificant, but the front-back confusions were significantly different between HRTFs on ipsilateral side and contralateral side. The results suggested that the individualization of HRTFs with ITDs/ILDs might be influenced by the spectrum of non-individual HRTFs.