Enhancement of ambisonic binaural reproduction using directional audio coding with optimal adaptive mixing

Headphone reproduction of recorded spatial sound scenes is becoming increasingly relevant to immersive audiovisual applications. Popular non-parametric reproduction methods, such as firstorder ambisonics (FOA), can now be surpassed through the use of perceptually-motivated parametric reproduction methods. One such established method is Directional Audio Coding (DirAC). The earlier version of DirAC for headphones was itself limited to FOA input and achieved binaural rendering through a virtual loudspeaker approach; resulting in a high computational overhead. Therefore, this paper proposes an improved DirAC method that directly synthesises the binaural cues based on the estimated spatial parameters. This method can accommodate higher-order Ambisonics (HOA) signals and has reduced computational requirements; thus, making it suitable for lightweight processing with fast update rates and head-tracking support. According to listening tests, when utilising only FOA signals, the method results in equivalent or higher spatial accuracy than third-order Ambisonics and significantly outperforms FOA reproduction.