Acoustic source localization in a reverberant environment by average beamforming

This paper presents a strategy for the application of acoustic beamforming to locate noise sources in a reverberant field. In the hypothesis of stationary phenomena, the average amplitude and standard deviation of the output of beamforming, obtained from different array locations, are calculated. The standard deviation, normalized by the maximum value, can be used for beamforming output weighting, so as to enhance the source contribution, which is space invariant, and to attenuate the mirrors and sidelobe peaks, whose spatial position changes with changes in array position. The availability of microphone signals acquired when moving the array to a different position also allows a super-array to be obtained, i.e. an array obtained considering all the data as coming from a unique array. In this way, the capability of the averaging procedure to reject mirrors effects and disturbances is combined with high resolution beamforming for application in reverberant fields. These improvements are extended to the entire frequency range, since the procedure is not greatly affected by signal wavelength. (C) 2009 Elsevier Ltd. All rights reserved.