Interaural Level Difference Optimization of Binaural Ambisonic Rendering

TY - JOUR

T1 - Interaural Level Difference Optimization of Binaural Ambisonic Rendering

AU - McKenzie, Thomas

AU - Murphy, Damian Thomas

AU - Kearney, Gavin Cyril

N1 - © 2019 by the authors

PY - 2019/3/23

Y1 - 2019/3/23

N2 - Ambisonics is a spatial audio technique appropriate for dynamic binaural rendering due to its sound field rotation and transformation capabilities, which has made it popular for virtual reality applications. An issue with low-order Ambisonics is that interaural level differences (ILDs) are often reproduced with lower values when compared to head-related impulse responses (HRIRs),which reduces lateralization and spaciousness. This paper introduces a method of Ambisonic ILD Optimization (AIO), a pre-processing technique to bring the ILDs produced by virtual loudspeaker binaural Ambisonic rendering closer to those of HRIRs. AIO is evaluated objectively for Ambisonic orders up to fifth order versus a reference dataset of HRIRs for all locations on the sphere via estimatedILD and spectral difference, and perceptually through listening tests using both simple and complex scenes. Results conclude AIO produces an overall improvement for all tested orders of Ambisonics, though the benefits are greatest at first and second order.

AB - Ambisonics is a spatial audio technique appropriate for dynamic binaural rendering due to its sound field rotation and transformation capabilities, which has made it popular for virtual reality applications. An issue with low-order Ambisonics is that interaural level differences (ILDs) are often reproduced with lower values when compared to head-related impulse responses (HRIRs),which reduces lateralization and spaciousness. This paper introduces a method of Ambisonic ILD Optimization (AIO), a pre-processing technique to bring the ILDs produced by virtual loudspeaker binaural Ambisonic rendering closer to those of HRIRs. AIO is evaluated objectively for Ambisonic orders up to fifth order versus a reference dataset of HRIRs for all locations on the sphere via estimatedILD and spectral difference, and perceptually through listening tests using both simple and complex scenes. Results conclude AIO produces an overall improvement for all tested orders of Ambisonics, though the benefits are greatest at first and second order.

KW - Ambisonics;

KW - binaural Ambisonic rendering;

KW - interaural level difference

KW - virtual loudspeaker;

KW - binaural synthesis

UR - https://www.mdpi.com/2076-3417/9/6/1226

U2 - 10.3390/app9061226

DO - 10.3390/app9061226

M3 - Article

SN - 2076-3417

VL - 9

JO - Applied Sciences

JF - Applied Sciences

IS - 6

M1 - 1226

ER -