Assessment of inter-IC sound microelectromechanical systems microphones for soundscape reporting

Acoustic parameters obtained from calibrated acoustic equipment are part of the minimum soundscape reporting requirements as stated in Annex A of ISO 12913-2. To dynamically monitor the acoustic environment of a large area, a large network of acoustic sensors could be deployed, albeit at significant cost. Micro-Electro-Mechanical Systems (MEMS) microphones offer compact, low-cost and high-performance alternatives to traditional analog microphones. In particular, the use of Inter-IC Sound (IS) communication allows MEMS microphones to be conveniently used in concert with I2S output interfaces for sound actuation. The performance of several IS MEMS Microphones was compared to that of an IEC 61094-4:1996 WS2F microphone in an anechoic chamber and a series of digital filters was designed to compensate for the differences in frequency response. The noise floor, compensated frequency response, acoustic parameter accuracy of IS MEMS were evaluated and recommendations regarding the suitability of the IS MEMS were provided.