Noise reduction system using signal and noise level detectors in frequency domain

We have proposed the noise reduction system using signal and noise level detectors. An input spectrum and a noise spectrum are detected in real-time and then noise reduction is achieved by subtracting the detected noise spectrum from the input one. This system requires the noise subtraction coefficient in order to reduce the difference between the detected noise level and its true one. In the conventional system, it was set constant empirically. In this paper, we propose an automatic setting method of the noise subtraction coefficient. The effectiveness of the proposed method is confirmed through computer simulations.