Theoretical analysis of musical noise in generalized spectral subtraction: Why should not use power/amplitude subtraction?

In this paper, we provide a new theoretical analysis of the amount of musical noise generated via generalized spectral subtraction based on higher-order statistics. Power spectral subtraction is the most commonly used spectral subtraction method, and in our previous study a musical noise assessment theory limited to the power spectral domain was proposed. Therefore, in this paper, we propose a generalization of our previous theory on spectral subtraction for arbitrary exponent parameters. We can thus compare the amount of musical noise between any exponent domains from the results of our analysis. We also clarify that less musical noise is generated when we choose the lower exponent spectral domain; this implies that there is no theoretical justification for using power/amplitude spectral subtraction.