Binaural audio requires the use of crosstalk cancellation if reproduced using loudspeakers. A three-listener crosstalk cancellation system has been designed and built as part of this work. Simulations for di↵erent loudspeaker distributions are presented and a large system span is shown to increase low-frequency crosstalk cancellation performance whilst a denser loudspeaker distribution in front of a given listener increases mid to high-frequency crosstalk cancellation. The system's performance under perturbation of the listeners and loudspeakers is investigated and at high frequencies loudspeakers further away from any given listener are shown to be a↵ected more by perturbations than those nearer the listener. To this issue, a novel implementation of weighting loudspeaker source strengths using loudspeaker dependent regularization is developed and optimised for use in this system. Hence, at high frequencies just loudspeakers close to the listener are used. This is shown to create a more robust solution than traditional crosstalk cancellation filter design when the system has undergone perturbations.

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This work introduces a new theory for spatial audio recording and reproduction named Higher Order Stereophony. Through the use of the Taylor expansion, the technique accurately reproduces a sound field across a line that is orientated as the interaural axis of a listener, to attempt to recreate a set of desired binaural signals. The technique utilises loudspeaker amplitude panning, and is shown to encompass in its framework traditional Stereophony approaches such as the stereo sine law. Therefore, the technique expands Stereophony to higher orders and more loudspeakers, leading to a greater frequency range of accurate reproduction, in a similar manner to Higher Order Ambisonics. Higher Order Stereophony is shown to exhibit many similarities to Higher Order Ambisonics, and decoders to transition between the different sound field representations are derived. Higher Order Stereophony is also re-derived through a mode matching approach using a subset of spherical harmonics, those with degree index equal to zero only. The theoretical results are then validated through experimental measurements using various microphone arrays, considering the reproduced sound field across a single line and the reproduced spherical harmonic coefficients of the sound field.

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Binaural rendering is a technique that seeks to generate virtual auditory environments that replicate the natural listening experience, including the three-dimensional perception of spatialized sound sources. As such, real-time knowledge of the listener's position, or more specifically, their head and ear orientations allow the transfer of movement from the real world to virtual spaces, which consequently enables a richer immersion and interaction with the virtual scene. This study presents the use of a simple laptop integrated camera (webcam) as a head tracker sensor, disregarding the necessity to mount any hardware to the listener's head. The software was built on top of a state-of-the-art face landmark detection model, from Google's MediaPipe library for Python. Manipulations to the coordinate system are performed, in order to translate the origin from the camera to the center of the subject's head and adequately extract rotation matrices and Euler angles. Low-latency communication is enabled via User Datagram Protocol (UDP), allowing the head tracker to run in parallel and asynchronous with the main application. Empirical experiments have demonstrated reasonable accuracy and quick response, indicating suitability to real-time applications that do not necessarily require methodical precision.