Biography

I graduated from the Tonmeister course in June 2007 and joined the IoSR as a research student in October 2007. I completed my thesis, entitled "A Psychoacoustic Engineering Approach to Machine Sound Source Separation in Reverberant Environments", in September 2010 and joined the IoSR as a lecturer in October 2010. In my spare time I enjoy playing the saxophone, cycling and running, having completed the London Marathon in 2007 and 2012.

Research Interests

My research interests include modelling the precedence effect and binaural localisation, computational auditory scene analysis, and machine listening for the automated evaluation of audio quality.

Research Collaborations

Perceptually Optimised Sound Zones (POSZ)

Publications

Teaching

My teaching duties include:

• HE1 Audio Engineering & Recording Techniques A/B (Technical Ear Training)
• HE3 Video Engineering
• HE3 Technical Project (Audio Research Seminars)

Book a tutorial (IoSR members only)

Departmental Duties

I am currently the Assistant Director of Research at the IoSR and Admissions Tutor for the Tonmeister programme.

Downloads

Publications

Some of my publications, including my thesis, are available to download from the Surrey Research Insights website.

MUSHRA Max/MSP patcher (version 2.0)

This Max/MSP patcher is designed for conducting MUSHRA (MUltiple Stimulus with Hidden Reference and Anchor, see ITU-R BS.1534) listening tests. The patch allows the comparison of a number of stimuli (7 by default, although up to 10 is supported) and facilitates repeats. By default, the patch can compare seven processes applied to three music tracks, with two repeats, making a total of six pages. However, the patch can be easily adapted to accommodate a different number of stimuli and/or music tracks and/or repeats; the included documentation describes the procedure in detail. Version 2.0 will work with Max/MSP 4 or higher.

MUSHRA_patcher.zip

ABX Max/MSP patcher

This Max/MSP patcher (compatible with Max/MSP 4.6 or higher) implements an ABX listening test. The test is a discrimination task, assessing the listener's ability to hear differences in audio files that contain small impairments. The patcher chooses a reference stimulus and a test stimulus, which are randomly assigned to A and B. Either A or B is then randomly assigned to X. This listener must decide whether X is A or B. The patcher chooses the test stimulus from a pool of several audio files. The presentation of each audio file can be repeated a specified number of times. The presentation of all audio files and repeats is randomised.

A Localisation- and Precedence-based Binaural Separation Algorithm (version 1.0)

The separation software developed during my PhD is available below. It is based upon Palomäki et al.'s (2004) binaural processor for missing data speech recognition in the presence of noise and small-room reverberation. The software generates "cocktail party" mixtures of signals arising from two spatially–separate sound sources in real rooms and attempts to separate them using interaural cues enhanced by models of the precedence effect. Implemented precedence models include those proposed by Martin (1997), Faller & Merimaa (2004), Lindemann (1986) and Macpherson (1991). The software is written for Matlab and should work on most platforms and versions. It requires the signal processing toolbox and a compatible C compiler.

PrecSep_toolbox.zip

Binaural Room Impulse Responses Captured in Real Rooms

The Binaural Room Impulse Responses (BRIRs) used in the above software are packaged with it, but available separately and at a higher sampling frequency below. The responses were captured in real rooms at the university, with sound sources placed on the frontal azimuthal plane (±90°) in 5° increments. The package includes documentation on how and where the responses were captured. The BRIRs are stereo wave files, captured at 48 kHz, 16 bit, but also included down-sampled to 16 kHz.

Simulated Room Impulse Responses

This archive contains three groups of 11 sets of RIRs obtained from a room simulated in CATT-Acoustics modelling software. Each set has a different reverberation time that was varied by changing the absorption coefficient of all six surfaces to produce reverberation times in the interval [0,1] s. The room was shoebox-shaped with dimensions 6×4×3 m (l×w×h). The impulse responses were calculated with the receiver located in the centre of the room at a height of 2 m and the source at a distance of 1.5 m. The omnidirectional sound source was placed at head height on the frontal azimuthal plane (±90°) in 5° increments.

The sets are provided in three groups, with each group corresponding to a different receiver configuration. The three receiver configurations were: binaural, spaced omnidirectional, and mono omnidirectional. In the spaced omnidirectional case, the receivers were spaced by 16 cm – the approximate spacing of the ears in the binaural case. The mono omnidirectional case is provided for completeness.

The RIRs are mono or stereo wave files, simulated at 44.1 kHz, 16 bit, but also included down-sampled to 16 kHz.

Matlab Files

My Matlab community profile contains a selection of small functions that have arisen during the course my research.