Audio signal enhancement with recursive restoration employing deterministic degradation

An audio processing system, comprising:

• at least one processor;
• and a memory having instructions stored thereon that, when executed by the at least one processor, cause the audio processing system to:
• collect an input audio signal indicative of a mixture audio waveform, wherein the mixture audio waveform includes a target signal component and an interference signal component;
• generate an enhanced target signal, estimated by executing a recursive restoration operation iteratively until a termination condition is met, wherein the recursive restoration operation is configured to
• receive, in an initialization step, an input audio mixture as an initial degraded target signal estimate with an initial level of severity of degradation, wherein the initialization step and the recursive restoration operation use a restoration operator configured to restore a degraded target signal estimate conditioned on a level of severity of degradation, wherein the initialization step applies the restoration operator to the initial degraded target signal estimate conditioned on the initial level of severity to obtain a current target signal estimate, and
• execute a current iteration of the recursive restoration operation, the current iteration comprising degrading the current target signal estimate deterministically with a current level of severity less than a previous level of severity and applying the restoration operator conditioned on the current level of severity to obtain an updated enhanced signal estimate;
• and
• output the updated enhanced signal estimate as a target signal estimate.