Speech enhancement based on noise compensated magnitude spectrum

In this paper, a speech enhancement method based on noise compensation performed on short time magnitude spectra is presented following the geometric approach. Here the noise estimate to be subtracted from the noisy speech spectrum is proposed to be determined by exploiting the low frequency regions of noisy speech of the current frame rather than depending only on the initial silence frames. We argue that this approach of noise estimation offers the capability of tracking the time variation of the non-stationary noise. A noise estimation confidence parameter is also introduced to prevent the subtraction of the overestimated noise. A procedure is thus formulated to compensate for the distortion in the magnitude spectrum of the noisy speech signal. The noise compensated magnitude spectrum is then recombined with the noisy unchanged phase spectrum to produce a modified complex spectrum prior to synthesize an enhanced frame. Extensive simulations are carried out using NOIZEUS database in order to evaluate the performance of proposed method. It is shown in terms of objective measures, spectrogram analysis and informal subjective listening test that the proposed method consistently outperforms one of the state-of-the-art methods of speech enhancement from noisy speech corrupted by babble or car noise at high as well as very low levels of SNR.