Adaptive noise reduction using discrimination functions

A method of noise reduction based on discrimination function minimization (DFM) is presented. This method requires the definition of a function that discriminates between clean and noisy speech. A particular discrimination function is derived for a certain type of noise, such that the minimization of this function reduces the noise in the noisy speech signal. The DFM noise reduction method does not assume stationarity of the noise over an entire speech period. It is shown how an abrupt change in piecewise-stationary noise can be tracked. The method has been successfully applied to the reduction of automobile noise