Abstract
Keywords:
Beamforming, Noise, Noise Source Location, Pass-By Noise
Abstract
Demands for the reduction of road traffic noise have become increasingly stringent worldwide in recent years, and there is therefore an increasing requirement to reduce vehicle pass-by noise, its primary source. Sources of components of vehicle pass-by noise include the engine, the intake and exhaust systems and the tires, meaning that numerous components are involved and noise sources are distributed widely around the vehicle. Efficient reduction of pass-by noise therefore requires accurate identification of the noise sources which contribute most significantly to it the noise. The project discussed in this paper focused on the beamforming method for the analysis of the pass-by noise sources for vehicle, and investigated its applicability as a method of analyzing vehicle pass-by noise. This method combines multichannel sensors and signal processing technology, and enables rapid identification of all noise sources in a particular area and visual imaging of the distribution of these noise sources. The type and positioning of the beamforming microphone array best suited to the analysis of vehicle pass-by noise was determined, and this array was used in noise source identification tests employing artificial noise sources and actual vehicles. The results of these tests indicated that (1) The equipment satisfied the targets set for accuracy and dynamic range, and (2) The method would be effective in enabling reduction of vehicle pass-by noise when employed in analysis of its sources.