High frequency noise tends to be transient in nature, such as squeak and rattles in cabins or closure panels. Therefore, capturing and identifying the noise source can be very difficult.
Brüel & Kjær’s innovations within noise source identification (NSI) and acoustical mapping, have led to the Spherical Beamformer, which quickly creates a 360 degree sound field map overlaid with a picture of vehicle interior without making any assumptions about the sound field. Noise sources are mapped by differentiating sound levels based upon the direction from which they originate. The method is very quick, allowing a full map to be calculated from a single-shot measurement.
As the Spherical Beamformer is just one tool within Brüel & Kjær’s comprehensive Array Acoustics Suite, the data collected during testing can be stored and easily compared with data acquired using other NSI techniques. This integration allows the NVH engineer the possibility to identify important sub-sources on an object in terms of position, frequency content and sound power. Ranking of sub-sources may be used to identify where design changes will most effectively improve the overall noise radiation.Products: