Open Access

Acoustic Source Localization and Beamforming: Theory and Practice

EURASIP Journal on Advances in Signal Processing20032003:926837

DOI: 10.1155/S1110865703212038

Received: 17 February 2002

Published: 30 March 2003


We consider the theoretical and practical aspects of locating acoustic sources using an array of microphones. A maximum-likelihood (ML) direct localization is obtained when the sound source is near the array, while in the far-field case, we demonstrate the localization via the cross bearing from several widely separated arrays. In the case of multiple sources, an alternating projection procedure is applied to determine the ML estimate of the DOAs from the observed data. The ML estimator is shown to be effective in locating sound sources of various types, for example, vehicle, music, and even white noise. From the theoretical Cramér-Rao bound analysis, we find that better source location estimates can be obtained for high-frequency signals than low-frequency signals. In addition, large range estimation error results when the source signal is unknown, but such unknown parameter does not have much impact on angle estimation. Much experimentally measured acoustic data was used to verify the proposed algorithms.


source localization ML estimation Cramér-Rao bound beamforming

Authors’ Affiliations

Electrical Engineering Department, University of California, Los Angeles (UCLA)


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