A Two Stage Algorithm for Denoising of Speech Signal

Spectral Subtraction based speech denoising suffers the major problem of introduction of new type of noise called musical noise. In this paper we introduce a two stage algorithm for denoising of noisy speech signal by minimizing the musical noise and additive white Gaussian noise. The algorithm works in two stages. First spectral subtraction method is applied on the noisy speech signal after applying pre-emphasis filter. Since the speech is highly corrupted by white Gaussian noise (3 dB SNR), the method introduces a musical noise. The enhanced speech is the processed using Savitzky–Golay smoothing filter to reduce the musical noise. The various objective as well as subjective measures are evaluated for the two stage method and compared against the individual methods. The two stage algorithm produces enhanced speech signal having high perceptual quality and intelligibility.