Patent attributes
A method for restoring distorted speech components of an audio signal distorted by a noise reduction or a noise cancellation includes determining distorted frequency regions and undistorted frequency regions in the audio signal. The distorted frequency regions include regions of the audio signal in which a speech distortion is present. Iterations are performed using a model to refine predictions of the audio signal at distorted frequency regions. The model is configured to modify the audio signal and may include deep neural network trained using spectral envelopes of clean or undamaged audio signals. Before each iteration, the audio signal at the undistorted frequency regions is restored to values of the audio signal prior to the first iteration; while the audio signal at distorted frequency regions is refined starting from zero at the first iteration. Iterations are ended when discrepancies of audio signal at undistorted frequency regions meet pre-defined criteria.
