Analysis and Design of Head-Tracked Compensation for Bilateral Ambisonics

Date：Dec 2023

Teams:Ben-Gurion University of the Negev；Reality Labs Research

Writers:Or Berebi,Zamir Ben-Hur,David Lou Alon,Boaz Rafaely

PDF:Analysis and Design of Head-Tracked Compensation for Bilateral Ambisonics

Abstract

Virtual and augmented reality technologies demand high-quality spatial sound recording and playback through headphones. However, achieving high-quality binaural reproduction requires a complex recording system and a large number of microphones. To address this issue, a recent study proposed Bilateral Ambisonics, which involves capturing the sound-field using two low-order microphone arrays located ear-distance apart. We present an analytical analysis of the limitation of a previously suggested head-tracking compensation solution to Bilateral Ambisonics. An alternative approach is proposed to overcome these limits in which the translation operation is band-limited. A subjective evaluation and a listening test are provided and complement the findings of the analytical analysis. Results indicate that in a static scenario, compensating for small lateral head-rotations up to <inline-formula><tex-math notation=”LaTeX”>$\pm 30^{\circ }$</tex-math></inline-formula> with good accuracy is possible for microphone arrays of spherical harmonics (SH) order of 1 and for medium rotations of up to <inline-formula><tex-math notation=”LaTeX”>$\pm 60^{\circ }$</tex-math></inline-formula> with SH order of 2. When a dynamic scenario is considered, Bilateral Ambisonics of order 2 were comparable to High-order Ambisonics, and Bilateral Ambisonics of order 1 provided performance comparable to third order Ambisonics with MagLS.