Conformal mapping based on spherical array measurements: Noise source identification in a car cabin.

Abstract

Spherical beamforming based on spherical array is a technique well suited for in‐cabin noise source identification, especially from mid‐ to high frequencies. One aspect of these imaging techniques based on acoustic measurements is how to link detected acoustic sources with the environment. Two main alternatives are currently used. The first possibility is based on pictures of the environment: pictures are superimposed on the acoustic map for an easy identification of sources. The main advantages are its quickness for setup and also it is a good solution to efficiently keep track of any change in the environment. The second possibility is the use of a model describing the objects around the microphone array. It is an interesting solution to describe precisely the medium. But also in terms of accuracy, it provides the correct distances from objects to the acoustic sensor: the level of sources could be more accurately determined. This last option can therefore generate an acoustic map conformal to the surrou...