I am currently investigating spatial qualities of audio reproduction.
I work with Philip Jackson, Slawek Zielinski and Francis Rumsey.
Spreadsheet Tool for Loudness Equalisation Using LOUDAES.EXE and the NTI Acoustilyzer
A mathematical model for objective assessment of perceived spatial quality was devloped for comparison across the listening area of various sound reproduction systems: mono, two-channel stereo (TCS), 3/2 stereo (i.e., 5.0 surround sound), Wave Field Synthesis (WFS) and Higher Order Ambisonics (HOA). Models for mono, TCS and 3/2 stereo are based on conventional microphone techniques and loudspeaker configurations for each system. WFS and HOA models use circular arrays of thirty-two loudspeakers driven by signals derived from a virtual microphone array and the Fourier-Bessel spatial decomposition of the soundfield respectively. Directional localisation, ensemble width and ensemble envelopment of monochromatic tones, extracted from binaural signals, are analysed under a range of test conditions.
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Sound oressure plots for a reproduced monochromatic 600Hz wave. The blue and yellow contours enclose areas where the error between the original and reproduced soundfields is less than 20% and 50% respectively. The left hand plot is for a 3/2 stereo system and the right hand plot is for a 16th order 32-loudspeaker HOA system.
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Perceived angles calculated from Interaural Time Differences (ITDs) for a reproduced monochromatic 600Hz wave, with 5 degree (blue) and 10 degree (yellow) error contours. The left hand plot is for a 3/2 stereo system and the right hand plot is for a 16th order 32-loudspeaker HOA system.