REPORT lathoud-rr-05-13/IDIAP A Frequency-Domain Silence Noise Model Lathoud, Guillaume Magimai-Doss, Mathew Mesot, Bertrand EXTERNAL http://publications.idiap.ch/attachments/reports/2005/rr-05-13.pdf PUBLIC Idiap-RR-13-2005 2005 IDIAP Martigny, Switzerland To appear in ``Proceedings of INTERSPEECH 2005'' This paper proposes a simple, computationally efficient 2-mixture model approach to discrimination between speech and background noise. It is directly derived from observations on real data, and can be used in a fully unsupervised manner, with the EM algorithm. A first application to sector-based, joint audio source localization and detection, using multiple microphones, confirms that the model can provide major enhancement. A second application to the single channel speech recognition task in a noisy environment yields major improvement on stationary noise and promising results on non-stationary noise.