Compressing higher order ambisonics of a multizone soundfield

Abstract

At present, the majority of the studies in the area of multizone sound-field reproduction are focused on the decoding of the soundfield. In this work, we propose an approach to encode the multizone sound-field within the desired reproduction region based on higher order Ambisonics (HOA) formats. The B-format signals for the complex multizone soundfield can be derived based on the coefficients of a formulated planewave expansion. The multizone soundfield B-format signals are then compressed using two state-of-the-art audio codecs as if they were individual mono signals. The results confirm the effectiveness of this HOA-based multizone soundfield encoding. Additionally, a significant reduction on the encoding rate of the desired multizone soundfield with sufficient accuracy can be achieved by quantitatively analyzing the reproduction performance of the system. We use the acoustic energy contrast between the selected bright zone and quiet zone as the performance evaluation measure.