Linearly and Quadratically Constrained Least-Squares Decoder for Signal-Dependent Binaural Rendering of Ambisonic Signals

摘要

Ambisonics has been widely adopted for conveying immersive audio experiences via headphone-based sound scene reproduction. It is well known, however, that the inherent reduction of spatial resolution of order-limited Ambisonic scenes leads to blurred source images, reduced spaciousness and direction-dependent timbral artifacts when rendered for binaural playback. Signal-dependent rendering methods aim to remedy these shortcomings by enhancing the spatial resolution using a set of estimated sound field parameters or by injecting decorrelated signals. It has been shown that such methods can indeed improve the spatial quality of the rendered signals, however, parameter estimation errors and decorrelator artifacts oftentimes introduce audible signal artifacts. In this work we propose a signal-dependent method for binaural rendering of Ambisonic signals based on a constrained least-squares decoder. The proposed method enables faithful reproduction of a direct and a diffuse signal per time-frequency tile requiring only a single sound field parameter and avoiding the need of injecting decorrelated signals.