Horizontal plane HRTF interpolation using linear phase constraint for rendering spatial audio

Abstract

In this paper, a novel method of horizontal plane Head Related Transfer Function (HRTF) interpolation is proposed. As Interaural Time Difference (ITD) manifests itself as Interaural phase difference in spectral domain, linear phase constraints are imposed to compute the interpolated HRTFs. Hence the phase of the interpolated HRTF is constrained as a weighted linear combination of the phases of adjacent HRTFs. A weighted l2 norm error minimization is performed using these linear phase constraints. The performance of the proposed HRTF interpolation method is evaluated by computing Root Mean Squared Error (RMSE) between the interpolated HRTF and ground truth HRTF obtained from the CIPIC and SYMARE databases. Subjective evaluation is performed on the binaural audio that is rendered using interpolated HRTFs. It is noted from both RMSE and subjective evaluations that the proposed method performs reasonably better than the conventional HRTF interpolation methods.