Multiple incoherent sound source localization using a single vector sensor

With the Microflown acoustic particle velocity sensor, broadband acoustic vector sensors in air have become available. An assembled probe version is based upon three orthogonally placed acoustic particle velocity sensors and a single sound pressure sensor. This probe has also become available as a monolithic flat but 3D sound chip in early 2009. It has been shown that with a single vector sensor containing three particle velocity sensors and a microphone, the direction of a single sound source can be determined based on the three dimensional intensity vector. If the sound source is moving, the Doppler effect may be used to estimate the distance as well. When multiple acoustic vector sensors are used, the location of a single sound source in the three dimensional space can be found by triangulation based on the intensity vectors. However, these intensity based methods fail when multiple sources are present. Therefore research is presented to localize multiple sound sources. With simulations it will be shown that the correlation of the individual channels of the vector sensor can be used to determine the directions of at least two incoherent sound sources. These observations are checked by experiments in an anechoic room. In these experiments the direction of the incoherent sources is precisely known. The directions and strengths of these sources are reconstructed by processing the signals of the individual elements of a single vector sensor. It is proven that the directions and strengths of two sources can be distinguished with a single acoustic vector sensor.