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

Development of a range of comfort indices for earplugs to improve hearing protection for workers


In Québec, 360,000 workers are exposed daily to noise levels likely to induce hearing problems (EQCOTESST, 2011). Hearing loss is the most frequently documented occupational disease, and the number of affected workers is on the rise, as are the related compensation costs.

While the most effective solution to prioritize is noise reduction at the source, the use of personal hearing protection devices is sometimes the only feasible means of prevention. Hearing protectors are chosen on the basis of their noise attenuation capability, characterized by the Noise Reduction Rating (NRR) value measured in a laboratory. However, in the field, the real protection offered by hearing protectors is often less than expected because they are not worn properly or long enough, due to the discomfort experienced by workers.

A previous IRSST-funded project titled Development of tools and methods for better evaluating and improving workers’ personal hearing protection, proposed tools for better objective characterization of hearing discomfort, but these tools did not provide a means of classifying the overall discomfort associated with ear plugs.

In order to classify the discomforts associated with ear plugs more rigorously and to design more comfortable ear plugs, it is necessary to develop a range of indices, including the attributes of the main components of physical, auditory, functional and psychological comfort. The main aim of this project is therefore to design such a tool, called Range of indices of objectified comfort.

Additional Information

Type: Project
Number: 2015-0014
Status: Ongoing
  • Franck Sgard (IRSST)
  • Olivier Doutres (École de technologie supérieure)
  • Alain Berry (Université de Sherbrooke)
  • Jérémie Voix (École de technologie supérieure)
  • Nicolas Trompette (Institut national de recherche scientifique)
  • Éric Wagnac (École de technologie supérieure)
  • Alessia Negrini (IRSST)
  • Matt Carre (University of Sheffield)
  • Roger Lewis (University of Sheffield)
  • Steven Matcher (University of Sheffield)