A research project taking place at the University of Surrey is using psychoacoustics and engineering to investigate Perceptually Optimised Sound Zones (POSZ). Aiming to create conditions that reproduce sounds within confined areas of acoustical space and minimise crosstalk, the project has seen the construction of a near 360-degree structure that supports sixty-four Genelec 8020B monitors. Supplied by HHB Communications, the monitors used will be able to transfer to a series of other projects into sound field reproduction, 3D sound, spatial audio and perceptual experiments. For the current POSZ project, the Genelecs are mounted on the spherical frame and readings are then taken by a grid of microphones at different listening positions inside the structure.
The University’s Department of Electronic Engineering and the Institute of Sound Recording have pooled their knowledge to build on previous studies in multiple sound zones. The engineering team is developing methods to radiate sound so that audio is concentrated in dedicated sound zones (with minimal spill into other zones); the psychoacoustic research is developing a model of the perceived effect of interfering signals in a sound zone to quantify the performance of a system in a perceptually-relevant way.
The research project at Surrey has some implications for real-life situations such as multiple use of different sources within shared spaces: “If two people in a single room wish to listen to different items of audio – via a TV and PC for example – it is only really effective with headphones, which is extremely isolating,” said Phil Coleman, PhD research student at the University of Surrey. “What our project seeks to achieve is a way of effectively reproducing audio sources within confined zones while minimising any leaks to other users within the room.”
The grid of microphones that records the audio feed is made up of 48 mics in total, which feeds back to a computer. In addition to the Genelec 8020B speakers, HHB supplied six PreSonus DigiMaxD8 microphone pre-amplifiers and a 72-channel Motu audio/computer interface based around 24 I/O interfaces.