Application of Acoustic Holography to Measurement of Noise on an Operating Vehicle 930199
This paper describes a feasibility study of the acoustic holographic method to identify a noise source on an operating vehicle. A new acoustical holography method applicable to identification of a nonstationary noise source was assessed and developed. Based on the new method, a measurement system was made and applied to quantification of the noise source in the vehicle. The method was evaluated first for source identification capablity and confirmed by loudspeakers. The experimental approach was then applied to identify the location of vehicle tire noise under various steady state conditions. In this paper, an identification method of noise sources with relatively high power level is presented and the relationship between locations of tire noise sources under various operating conditions investigated. It was verified that this system was effective for the identification of not only ideal point acoustic sources such as loudspeakers, but also complex spatial and phase wavefronts generated from operating vehicles.