On the Use of Hearing Aid Algorithms in Industrial Noise: Balancing Speech Intelligibility and Hearing Protection

Hearing protection devices (HPDs) are widely used to mitigate the risks of noise-induced hearing loss in industrial environments. However, conventional HPDs can often hinder communication for workers with hearing loss. While those workers may rely on hearing aids in their daily lives, the potential benefits and associated risks of using such devices in noisy workplaces remain unexplored. This study evaluated the effects of different hearing aid signal processing algorithms on speech intelligibility and estimated noise exposure under industrial noise conditions to characterize the balance between communication and protection needed to develop solutions for workers with hearing loss. A digital hearing protection research platform integrating in-ear receivers and external microphones was configured as a real-time soundcard. Typical hearing aid algorithms, including linear amplification, Wide Dynamic Range Compression (WDRC), digital noise reduction (DNR), and compression limiting, were implemented in different configurations. Two groups, one with normal hearing and one with hearing loss, completed the Hearing in Noise Test (HINT) with a wood-working factory noise at two presentation levels, along with subjective ratings of listening effort and voice clarity and naturalness. Noise exposure for each configuration was also estimated. Results showed significant effects of signal processing strategies and noise presentation levels on both intelligibility and noise exposure. Combining DNR, WDRC and compression limiting showed promising results to balance intelligibility and noise exposure, particularly for participants with hearing loss. The findings emphasize the trade-off between auditory benefit and exposure risk, and call for greater awareness regarding the use of hearing devices in industrial noise.