Bandwidth extension for speech enhancement

Abstract

In real-world wideband noisy recordings of speech, the Signal-to-Noise ratios in the lower half spectra are typically higher than those observed in their upper half counterparts, due to the average frequency distribution of the speech energy. Speech enhancement algorithms therefore struggle to recover damaged high frequency components, thereby penalizing the output perceived quality of the enhanced signal. In this paper, it is proposed to use and adapt the concept of Bandwidth Extension in the context of speech enhancement so as to reinforce the high-frequency estimates of the clean speech. By allowing enhancement schemes to focus their resources on narrowband speech while synthesizing the rest of the signal, it is found that the overall quality can be improved, while reducing significantly the computational costs of the obtained method.