  We propose a system that gives a mobile robot the ability to separate
simultaneous sound sources. A microphone array is used along with a real-time
dedicated implementation of Geometric Source Separation and a post-filter that
gives us a further reduction of interferences from other sources. We present
results and comparisons for separation of multiple non-stationary speech
sources combined with noise sources. The main advantage of our approach for
mobile robots resides in the fact that both the frequency-domain Geometric
Source Separation algorithm and the post-filter are able to adapt rapidly to
new sources and non-stationarity. Separation results are presented for three
simultaneous interfering speakers in the presence of noise. A reduction of log
spectral distortion (LSD) and increase of signal-to-noise ratio (SNR) of
approximately 10 dB and 14 dB are observed.
