Wideband noise suppression supported by artificial bandwidth extension techniques

摘要

This contribution presents a wideband (50Hz – 7 kHz) speech enhancement system that is operating in the frequency domain. As a novel feature, techniques known from artificial bandwidth extension (BWE) are used to improve the spectral estimation process by exploiting the statistical dependencies between the low band (50Hz – 4kHz) and the high band (4–7kHz). Conventional noise suppression is used in the low band, while a novel approach is applied to the high band. Features from the processed (enhanced) low band signal are extracted and used to estimate subband energies of the high band. The weighting gains determined from these energy estimates are adaptively combined with conventional gains obtained in addition for the high band. The performance of the proposed method is shown to be consistently better than the conventional approach, especially at low input SNR values.