UNet-DenseNet for Robust Far-Field Speaker Verification

Far-field speaker verification (SV) has always been critical but challenging. Data augmentation is commonly used to overcome the problems arising from far-field microphones, such as high background noise levels and reverberation effects. On top of data augmentation, this paper tackles these problems by introducing a UNet-based speech enhancement (SE) module as a front-end processor for the speaker embedding module. To prevent the SE module from distorting speaker information, we propose two improvements to the speech enhancement-speaker embedding pipeline. (1) A UNet-DenseNet joint training scheme in which the UNet is optimized by both the MSE and speaker classification losses. (2) A semi-joint training scheme that stops the UNet training but continues the DenseNet training when overfitting of the UNet is detected. Extensive experiments on noise-contaminated Voxceleb1 and the VOiCES Challenge 2019 demonstrate the effectiveness of the two training schemes.