Analysis of noise emitted by an engine using an innovative 3D microphone positioning system

When making measurements around a noise source with a sound intensity probe, the position of the probe is required to create a noise map. Usually the measurement positions are fixed on a grid or are traced with an IR system. In this paper a case study is presented in which an innovative 3D measurement system for the positioning of the sound intensity probe is used. The position detection system uses acoustic waves to locate a point in three-dimensional space. The result is similar to what is obtained with beamforming systems, with the advantage that by carrying out a series of measurements with an intensity probe it was possible to analyse the noise emissions in a very precise and punctual way, with the desired spatial resolution (within the directionality limits of the acoustic waves that is a function of frequency). In addition, the positioning system is economical and requires just a multichannel soundcard and few other components