Joint DNN-Based Multichannel Reduction of Acoustic Echo, Reverberation and Noise

--We consider the problem of simultaneous reduction of acoustic echo, reverberation and noise. In real scenarios, these distortion sources may occur simultaneously and reducing them implies combining the corresponding distortion-specific filters. As these filters interact with each other, they must be jointly optimized. We propose to model the target and residual signals after linear echo cancellation and dereverberation using a multichannel Gaussian modeling framework and to jointly represent their spectra by means of a neural network. We develop an iterative block-coordinate ascent algorithm to update all the filters. We evaluate our system on real recordings of acoustic echo, reverberation and noise acquired with a smart speaker in various situations. The proposed approach outperforms in terms of overall distortion a cascade of the individual approaches and a joint reduction approach which does not rely on a spectral model of the target and residual signals. Index T erms--Acoustic echo, reverberation, background noise, joint distortion reduction, expectation-maximization, recurrent neural network. The near-end speaker can be a few meters away from the microphones and the interactions can be subject to several distortion sources such as background noise, acoustic echo and near-end reverberation. Each of these distortion sources degrades speech quality, intelligibility and listening comfort, and must be reduced. Single-and multichannel filters have been used to reduce each of these distortion sources independently. They can be categorized into short nonlinear filters that vary quickly over time and long linear filters that are time-invariant (or slowly time-varying). Short nonlinear filters are generally used for noise reduction [1]. They are robust to the fluctuations and nonlinearities inherent to real signals. Long linear filters can be required for dereverberation [2] and echo reduction [3].