Efficient localization and tracking of two acoustic sources using particle filters with swarm intelligence

In this paper we consider the problem of localizing multiple acoustic sources in reverberant environments. The solution that we propose is based on the combination of two techniques. A blind source separation (BSS) method known as TRINICON [5] is applied to the signals acquired by the microphone arrays. The TRINICON de-mixing filters are used to obtain the Time Differences of Arrival (TDOAs), which are related to the source location through a nonlinear function. A particle filter is then applied in order to localize the sources. Particles move according to a swarm-like dynamics, which significatively reduces the number of particles involved. We discuss results for the case of two sources and four microphone pairs. Experimental results confirm that the same localization accuracy (measured in terms of RMS error) can be achieved using 25 particles instead of 300. In addition, we propose a method, based on detecting source inactivity, which overcomes the ambiguities that intrinsically arise when only two microphone pairs are used.