Convolution-augmented transformers (Conformers) are recently proposed in
various speech-domain applications, such as automatic speech recognition (ASR)
and speech separation, as they can capture both local and global dependencies.
In this paper, we propose a conformer-based metric generative adversarial
network (CMGAN) for speech enhancement (SE) in the time-frequency (TF) domain.
The generator encodes the magnitude and complex spectrogram information using
two-stage conformer blocks to model both time and frequency dependencies. The
decoder then decouples the estimation into a magnitude mask decoder branch to
filter out unwanted distortions and a complex refinement branch to further
improve the magnitude estimation and implicitly enhance the phase information.
Additionally, we include a metric discriminator to alleviate metric mismatch by
optimizing the generator with respect to a corresponding evaluation score.
Objective and subjective evaluations illustrate that CMGAN is able to show
superior performance compared to state-of-the-art methods in three speech
enhancement tasks (denoising, dereverberation and super-resolution). For
instance, quantitative denoising analysis on Voice Bank+DEMAND dataset
indicates that CMGAN outperforms various previous models with a margin, i.e.,
PESQ of 3.41 and SSNR of 11.10 dB.

本文提出了基于 Conformers 的度量生成对抗网络（CMGAN）用于时频域中的语音增强，并且在消除噪声、去混响和超分辨率等三个语音增强任务上取得了优越的性能。