JMIR Publications

ABSTRACT

Background:

In order to present virtual sound sources via headphones spatially, head-related transfer functions (HRTFs) can be applied to audio signals. In this so-called binaural virtual acoustics, the spatial perception may be degraded if the HRTFs deviate from the true HRTFs of the listener.

Objective:

In this study, participants wearing virtual reality (VR) headsets performed a listening test on the 3D audio perception of virtual audiovisual sound scenes, thus enabling us to investigate the necessity and influence of the individualization of HRTFs.

Methods:

For the evaluation, 39 subjects rated individualized and non-individualized HRTFs in an audiovisual virtual scene on the basis of five perceptual qualities: localizability, front-back position, externalization, tone color, and realism. The VR listening experiment included two tests: In the first test, subjects evaluated their own and the general HRTF from the MIT KEMAR database and in the second test, their own and two other non-individualized HRTFs from the ARI HRTF database. For the experiment, two subject-specific, non-individualized HRTFs with a minimal and maximal localization error deviation were selected according to the localization model in sagittal planes.

Results:

With the Wilcoxon signed-rank test for the first test, ANOVA for the second, and a sample size of 78, the results show significance in all perceptual qualities (P≤.05), except for the front-back position between own and minimal-deviant-non-individualized HRTF (P=0.06).

Conclusions:

This suggests that sounds filtered by individualized HRTFs compared to non-individualized HRTFs are considered easier to localize, easier to externalize, more natural in timbre and more realistic.