Localization Cues Preservation in Hearing Aids by Combining Noise Reduction and Dynamic Range Compression

Dynamic range compression (DRC) and noise reduction algorithms are commonly used in hearing aids. They are known to have opposite objectives concerning the Signal-to-Noise Ratio (SNR) and to affect negatively the localization performance. Yet, the study of their interaction received few attention. In this work, we improve an existing combined approach of DRC and noise reduction to bridge the gap between the algorithms proposed independently in their respective communities. The proposed solution is then compared to state-of-the-art algorithms thanks to objective criteria assessing the spatial fidelity preservation, the SNR improvement and the output dynamic range reduction. Experimental results show that the standard serial concatenation of noise reduction and DRC stages is unable to improve the SNR and preserve the noise component acoustic characteristics. They suggest that the proposed design restores the noise localization cues and manages to improve the output SNR.