Spectral smoothing method for noise reduction

Abstract

A system configured to perform low input-output latency noise reduction in a frequency domain is provided. The real-time noise reduction algorithm performs frame by frame processing of a single-channel noisy acoustic signal to estimate a gain function. Accurate noise power estimates are achieved with the help of minimum statistics approach followed by a voice activity detector. The noise power and gain values are smoothed to remove any external artifacts and avoid background noise modulations. The gain values for individual frequency bands are weighted and smoothed to reduce distortion. To obtain distortionless output speech, the system performs curve fitting by separating the frequency bands into multiple groups and applying a Savitzky-Golay filter to each group. The final gain values generated by these filters are multiplied with the noisy speech signal to obtain a clean speech signal.