Limitations of the spectrum masking technique for blind source separation

Abstract

The objective of this study is to analyze the limitations of techniques for blind source separation (BSS) of convolved mixtures based on time-frequency domain binary masking. In this study, initially, the limitations of the spectrum masking technique as a function of the reverberation time of the signals that compose the mixture to be separated are analyzed. When the ideal masks are known, a separation of about 9 dB is obtained for the case of an environment with reverberation time less than 300 ms. From this point on, as the reverberation time increases, the signals that compose the mixture spread over the time-frequency plane, progressively reducing the separation process performance. Finally, a subjective test to measure the intelligibility of the separated voice signals using an ideal binary mask is also proposed for different reverberation times. © Springer-Verlag Berlin Heidelberg 2009.