On the Localization of Sound Sources with Moving Microphones

Abstract:
This contribution describes a novel method for visualizing sound sources using a rotating linear array of a few digital microphones. The rotating array scans the incident sound field on a circular area. While the reduced hardware complexity allows for the design of a lightweight, handheld sound imaging device, the algorithmic portion of the measurement system requires special attention. In fact, established methods of sound imaging like beamforming and nearfield holography cannot be applied to signals stemming from moving sensors. The proposed method of computing an acoustic image using the described measurement setup is based on compensating the moving microphone signals for Doppler distortions and evaluating the coherence of the resulting signals with a non-moving reference microphone for each point in the acoustic image. The method is evaluated in the context of leakage detection in automotive structures.