Evaluation of Multichannel Dynamic Range Compression Algorithm for Hearing Aid Devices

Nearly 432 million adults across the world currently have disabling hearing loss, and 2.5 billion people are projected to have some degree of hearing loss in the next 25 years, per the World Health Organization. People with hearing impairments can benefit from hearing aid devices to be more active in daily life where they will come across multitudes of sounds of varying frequencies and noise levels. One crucial reason noted for the low usage of hearing aid devices is the accessibility and affordability of these devices. Smartphones and tablets have recently become valuable devices due to their availability, powerful built-in features, and user friendliness. In this paper, we present and analyze an open-source multichannel dynamic range compression algorithm, an indispensable part of the signal processing pipeline for the hearing aid application. It provides optimal fitting of received signals by adjusting the frequency-dependent gain function according to the individual's hearing sensitivity levels. This work examines how the algorithm automatically adjusts the gains at sixoctave frequency bands for optimal speech intelligibility and comfort for the user with the improvements in hearing being assessed by comparing the audiograms of a hearing impaired patient with and without the use of a hearing aid.