Noise pollution investigation takes advantage of two common methods of
diagnosis: measurement using a Sound Level Meter and acoustical imaging. The
former enables a detailed analysis of the surrounding noise spectrum whereas
the latter is rather used for source localization. Both approaches complete
each other, and merging them into a unique system, working in realtime, would
offer new possibilities of dynamic diagnosis. This paper describes the design
of a complete system for this purpose: imaging in realtime the acoustic field
at different octave bands, with a convenient device. The acoustic field is
sampled in time and space using an array of MEMS microphones. This recent
technology enables a compact and fully digital design of the system. However,
performing realtime imaging with resource-intensive algorithm on a large amount
of measured data confronts with a technical challenge. This is overcome by
executing the whole process on a Graphic Processing Unit, which has recently
become an attractive device for parallel computing