Acoustic noise reduction by two dimensional spectral smoothing and spectral amplitude transformation

We will describe a noise reduction method which diffuses and suppresses the noise component, while concentrating and enhancing speech formant information. Two Dimensional Spectral Smoothing (TDSS) is applied over a time sequence of spectral envelope to diffuse noise and concentrate formant information. After consonant enhancement, Non-linear Spectral Amplitude Transformation (NSAT) is carried out to further suppress the noise component and enhance formant information. This noise reduction method has proven to be superior to the conventional frequency subtraction method.