Beyond the Narrowband Approximation: Wideband Convex Methods for Under-Determined Reverberant Audio Source Separation

We consider the problem of extracting the source signals from an under-determined convolutive mixture assuming known mixing filters. State-of-the-art methods operate in the time-frequency domain and rely on narrowband approximation of the convolutive mixing process by complex-valued multiplication in each frequency bin. The source signals are then estimated by minimizing either a mixture fitting cost or a 1 source sparsity cost, under possible constraints on the number of active sources. In this article, we define a wideband 2 mixture fitting cost circumventing the above approximation and investigate the use of a 12 mixed-norm cost promoting disjointness of the source timefrequency representations. We design a family of convex functionals combining these costs and derive suitable optimization algorithms. Experiments indicate that the proposed wideband methods result in a signal-to-distortion ratio improvement of 2 to 5 dB compared to the state-of-the-art on reverberant speech mixtures....

• Type: Journal
• Year: 2010
• Where: TASLP
• Authors: M. Kowalski, Emmanuel Vincent, Rémi Gribonval
• Keywords: Convolutive Mixing Process, Software Engineering, Source Sparsity Cost, TASLP 2010, Under-determined Convolutive Mixture