Efficient Binaural Rendering of Spatially Extended Sound Sources
Carlotta Anemüller, Alexander Adami, and Jürgen Herre
Published in the Journal of the Audio Engineering Society - Special Issue on Audio for Virtual and Augmented Reality
Abstract
In virtual/augmented reality or 3D applications with binaural audio, it is often desired to render sound sources with a certain spatial extent in a realistic way. A common approach is to distribute multiple correlated or decorrelated point sources over the desired spatial extent range, possibly derived from the original source signal by applying suitable decorrelation filters. Based on this basic model, a novel method for efficient binaural rendering of spatially extended sound sources is proposed. Instead of rendering each point source individually, the target auditory cues are synthesized directly from just two decorrelated input signals. This procedure comes with the advantage of low computational complexity and relaxed requirements for decorrelation filters. A subjective listening test shows that the output of the proposed method is perceptually almost identical to the output of the basic rendering model. The technique is part of the Reference Model architecture of the upcoming MPEG-I Immersive Audio standard.
Audio Examples
The following examples are a subset of the items included in the listening test.
- Center: source reproduced at the center of the considered spatial extent range (not used in the listening test)
- Reference signal: reference signal, generated by distributing a number of decorrelated point sources over the considered spatial extent range
- Proposed method: output of the proposed method
Note that for the pink noise source signal no decorrelator was employed. Instead, incoherent noise sequences were used both as input to the proposed method and for generation of the reference signal.
Piano
Vocal quartet
Pink noise