Browser-Based Webcam Head-Tracked Ambisonics (WHAM)

This paper documents the development of a Higher Order Ambisonic (HOA) real-time head-tracked auralisation platform. Headphone-based audio is decoded binaurally without needing specialist head-tracking hardware using open-source libraries augmented for this project. The room scanning and head-tracked presentation technique discussed can provide accurate auralisation of real (captured/measured) and/or modelled spaces using up to 15th-order Ambisonics, much higher than current Ambisonic microphone technology allows. The differences between measuring the acoustic response of a space using Ambisonic microphones and rotated Head and Torso Simulators (HATS) are discussed, along with the importance of removing the left/right symmetry assumption used in current Ambisonic to Binaural implementations. A Dynamic Binaural Reverberation Acquisition Technique (D-BRAT) is introduced, allowing for a full 3D binaural capture and reproduction of an acoustic space while allowing dynamic head rotation by transformation into the Ambisonic, Spherical Harmonic domain. Open-source Software has been created (based on JSAmbisonics) to allow this Binaural Room Impulse Response (BRIR) Data to be auditioned using up to 15th-order Ambisonics with dynamic head rotations considered in real-time with accompanying 360-degree graphics display. A working example can be found at: https://brucewiggins.co.uk/WHAM/.