5th International Conference on Spoken Language Processing
Spectral noise subtraction has the drawback of generating residual noise with musical character, the so-called musical noise. We propose a simple modification of the filter coefficients calculation in form of a recursion to the previous coefficient. This recursion results in a switching mechanism of the spectral subtraction gain, in the way that speech pauses are processed with a nearly constant very low gain and speech components are processed with a nearly constant high gain. Because of the switching mechanism the generation of musical noise is almost completely avoided. The well known approach of Ephraim and Malah has a similar mechanism, but the new recursive scheme is much easier for implementation yet yielding comparable or sometimes better performance than the other approach.
Bibliographic reference. Linhard, Klaus / Haulick, Tim (1998): "Spectral noise subtraction with recursive gain curves", In ICSLP-1998, paper 0109.