IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

Development of a Voice-based Method for Objective Occlusion Effect Measurement


Hearing protectors are the most commonly used short-term hearing protection solution in the workplace. However, the ear canal occlusion effect causes a change in the wearer’s perception of his or her own voice and amplification of physiological noise, particularly when ear plugs are worn. Hearing protectors can thus be uncomfortable to wear, causing them to be used less often.

There are methods for quantifying occlusion effect in human subjects, but there is no consensus on the most effective method. In addition, the existing methods are not standardized.

In an earlier project entitled Development of tools and methods for better evaluating and improving workers’ personal hearing protection (0099-7630), a method based on microphone measurements and vocal effort was developed. This method seems to give good results, and is a first step towards developing a method for objective measurement of occlusion effect.

The purpose of this research project is to suggest a methodology for objective and reliable measurement of occlusion effect based on microphone measurements and to identify precise indicators for quantifying this effect.
In the longer term, we hope to create a measuring device that could be used to quantify occlusion effect in the workplace and provide data for awareness and training purposes.