A new method to locate sound sources by searching the minimum value of error function

This paper describes a new method to locate sound sources using many sensors. Spectra of all the sensor outputs are calculated by discrete Fourier transform. In the proposed method, following parameters are assumed; (1) the number of sound sources, (2) a position of each sound source, and (3) the spectrum of the O-th sensor output due to each sound source. The spectra of all the sensor outputs are estimated using the parameters under the assumption of free field. Then, introduced is an error function which is the mean-square value of the difference between the calculated spectra and the estimated ones. By changing the values of the parameters, the minimum value of the error function is searched. When the error function takes the minimum value, the parameters represent the estimates; the number of sound sources, and the positions and spectra of the sound sources. By inverse Fourier transforming the estimated spectra, the wave form of a specified sound source can be obtained.