Digital Earplug Featuring Combined Noise Dosimetry and Electrocochleography: a Proof of Concept.

Résumé

Electrocochleography (ECochG) is a promising electrophysiology measure that evaluates cochlear function and identifies different auditory disorders. ECochG measures inner ear potentials generated in response to acoustic simulation. Recent studies on cochlear synaptopathy have shown that ECochG can detect insults to auditory nerve fibers following noise exposure. These damages go undetected by routine audiology testing such as audiometry. Therefore, ECochG could be used to identify auditory damage during excessive noise exposure in a noisy workplace, and thus, ultimately help to prevent noise-induced hearing loss. To this aim, a dedicated electronic earpiece has been designed. It features passive hearing protection and can continuously monitor ECochG during a wearer’ shift. A pair of such earpiece is wired to a dedicated hardware device, dubbed eCoGeers, with a microcontroller and several analog-to-digital converters for ECochG potentials and audio signals processing. The synchronization aspect between both data acquisitions is paramount for accurate noise-exposure and inner ear integrity monitoring. To validate the prototype’s capabilities, tests have been conducted by sending a known ECochG stimulus as an electrical input to the earpiece device and by reading its low voltage on the prototype earpiece. Thus, to successfully extracting the original ECochG stimulus from the electrical noise floor. This research paves the way for a future device that could monitor noise exposure and auditory damage during a work shift. This device could ultimately warn the wearer when a significant damage has been detected and contribute to better noise-induced hearing loss prevention programs in the workplace.