MEMS microphones to map noise pollution

The DREAMSys (a Distributed Remote Environmental Array and Monitoring System) uses a wireless array of low-cost MEMS microphones to provide a means of collecting noise data over a widespread area, for the purpose of augmenting the production and validation of noise maps.

The technology was developed through a collaboration between the UK’s National Physical Laboratory (NPL), sound level meter manufacturer Castle Group, defence technology firm Qinetiq and Hoare Lea Acoustics. Their work was supported in part by the Technology Strategy Board.

MEMS microphones are already used widely in mobile phone and computing applications, but have yet to be exploited for precision noise measurements. This is partly because commercially available devices were not designed for such purposes and therefore their performance characteristics were largely unknown in relation to measurement applications.

So a key question before attempting to use MEMS microphones for measurement was how their performance compared with conventional instrumentation grade condenser microphones.