Vertical localization of noise sources on passenger caw with a microphone array
Type de document
COMMUNICATION AVEC ACTES INTERNATIONAL (ACTI)
Résumé / Abstract
The knowledge of the noise sources heights on a pass-by vehicle is important for traffic prediction models. The noise emitted by a light vehicle at usual speeds is composed of the rolling noise (tyre-road noise) and the mechanically originated noise (engine, exhaust system). The rolling noise sources are intrinsically located near the road. In order to get information about the vertical distribution and the strength of mechanical sources, we consider a non-moving vehicle and a linear vertical microphone array located several meters away. By scanning the focus of the beamformed array over some vertical plane, we may draw noise maps of the vehicle, in third-octave subbands and as a function of the engine rpm. The noisiest areas are thus identified for the side or the front emission of the vehicle. Most of them are located under the vehicle body and read the array after some road reflection.