Binaural reproduction using bilateral ambisonics

Binaural reproduction plays an important role in virtual and augmented reality applications. The rendering of binaural signals using Spherical-Harmonics (SH) representation gives the flexibility to control the reproduced binaural signals, by using algorithms that operate directly in the SH domain. However, in most practical cases, the binaural reproduction is order-limited, which introduces truncation error that has a detrimental effect on the perception of the reproduced signals. A recent study showed that pre-processing of the Head-Related Transfer Function (HRTF) by ear-alignment reduces its effective SH order. In this paper, a method to incorporate the ear-aligned HRTF into the binaural reproduction process using a new Ambisonics representation of the sound field formulated at the two ears, denoted here as Bilateral Ambisonics, is presented. Application of this method yields a significant improvement in the perceived audio quality of order-limited binaural signals.