Effects of wide dynamic range compression on speech signals with respect to reverberation

Abstract

The sound perception in enclosed spaces is dominated by the room acoustics properties of the enclosures. Today, it is known that reverberation generated by walls and obstacles challenges hearing-impaired people, even with hearing aids, and several studies have been conducted to address this problem. However, relatively little is known about how various signal processing blocks (i.e., beamforming, wide dynamic range compression) within hearing aids affect the reverberation content of the speech signals. Aim of this work was to investigate and quantify the effects of wide dynamic range compression on the reverberant component of speech signals employing both subjective and objective methods. Several objective metrics which correlate with reverberation were applied on the speech signals before and after the compression. Moreover, a listening test with 14 normal hearing participants was performed to assess whether the changes in the reverberation content of the compressed signals were perceivable. The perceptual results show that the gain model changed the perception of reverberation of the speech signals tested. Finally, the correlation between the objective metrics and the perceptual results of the listening test was then investigated, indicating increased reverberation content for the compressed signals.