Using Spherical Beamforming to Evaluate Wind Noise Paths

Microphone array based techniques have a growing range of applications in the vehicle development process. This paper evaluates the use of Spherical Beamforming (SB) to investigate the transmission of wind-generated noise into the passenger cabin, as one of the alternative ways to perform in-vehicle troubleshooting and design optimization. On track measurements at dominant wind noise conditions are taken with the spherical microphone array positioned at the front passenger head location. Experimental diligence and careful processing necessary to enable concise conclusions are briefly described. The application of Spherical Harmonics Angularly Resolved Pressure (SHARP) and the Filter-And-Sum (FAS) algorithms is compared. Data analysis variables, run-to-run repeatability and system capability to identify design modifications are studied. It is demonstrated that the Spherical Beamforming is a powerful tool to visualize dominant noise paths in vehicle, providing valuable information for the wind noise control at the transmission paths rather than using the standard single microphone operational data at the observer location.