Localization of sound sources by means of unidirectional microphones

This paper describes the results of a new approach devoted to the localization of ground borne acoustic sources. It is demonstrated that an array made of at least three unidirectional microphones can be exploited to identify the position of the source. Sound features extracted either in the time domain or in the frequency domain are used to localize the direction of the incoming sound. This information is then fed into a semi-analytical algorithm aimed at identifying the source location. The novelty of the method presented here consists in the use of unidirectional microphones rather than omnidirectional microphones and in the ability to extract the sound direction by considering features like sound amplitude rather than the time of arrival. Experimental tests have been undertaken in a closed environment and have demonstrated the feasibility of the proposed approach. It is believed that this method may pave the road toward a new generation of reduced-size sound detectors and localizers, and future work is described in the conclusions. © 2009 IOP Publishing Ltd

USE OF MICROPHONE DIRECTIVITY FOR THE LOCALLIZATION OF SOUND SOURCES

In a recent paper [1] the proof-of-concept of a novel approach for the localization of sound source was demonstrated. The method relies on the use of unidirectional microphones and amplitude-based signals' features to extract information about the direction of the incoming sound. By intersecting the directions identified by a pair of unidirectional microphones, the position of the emitting source can be identified.In this study we expand the work presented in that paper by assessing the effectiveness of the approach for the localization of an acoustic source in an indoor setting. As the method relies on the accurate knowledge of the microphones directivity, analytical expression of the acoustic sensors polar pattern were derived by testing them in an anechoic chamber. Then an experiment was conducted in a classroom-type environment by using an array of three unidirectional microphones. The ability to locate the position of a commercial speaker placed at different position is discussed.It is believed that this method may pave the road toward a new generation of reduced size sound detectors and localizers