ILO Home
Go to the home page
Site map | Contact us Français | Español

CISDOC database

Document ID (ISN)111830
CIS number 11-0555
ISBN(s) 978-2-89631-504-8
Year 2010
Convention or series no. Etudes et recherches - Rapport R-662
Author(s) Nélisse H., Gaudreau M.A., Boutin J., Laville F., Voix J.
Title Study of sound transmission through hearing protectors and application of a method for evaluating their efficiency in the workplace - Part 1 - Field study (revised version)
Original title Etude de la transmission sonore à travers les protecteurs auditifs et application d'une méthode pour évaluer leur efficacité en milieu de travail - Partie 1 - Etude terrain (version révisée) [in French]
Bibliographic information Institut de recherche Robert-Sauvé en santé et en sécurité du travail du Québec (IRSST), 505 boul. de Maisonneuve Ouest, Montreal (Quebec) H3A 3C2, Canada, 2010. x, 95p. Illus. 49 ref.
Internet access R-662.pdf [in French]
Abstract The method for evaluating the noise attenuation characteristics of hearing protectors is based on laboratory tests. However, many studies have shown that the actual effectiveness of this protective equipment is, more often than not, much lower than the results thus obtained. This study examined the time evolution of the performance of this equipment during one work shift, with 24 workers, in different sound environments, in Quebec, Canada. This mainly enabled them to develop a method for measuring the real effectiveness of earmuffs and moulded ear plugs, and then to compare it to measurements taken in the laboratory. Findings show protection values lower than those documented by the manufacturers (measured in the laboratory); for a given worker, the protection varies significantly in relation to the time during a work shift; the protection can vary greatly from one worker to the next but also from one ear to the other for a given worker. The developed attenuation index shows a high dependency on the frequency spectra of the ambient noise, thus highlighting the inadequacy of some hearing protectors at low frequencies and the importance of properly understanding the ambient noise so that a judicious choice of hearing protectors can be made.
Descriptors (primary) noise level; equipment testing; sound attenuation; hearing protection
Descriptors (secondary) comparative study; earplugs; earmuffs; public OSH institutions; report; description of technique
Document type E - Books, reports, proceedings
Country / State or ProvinceQuebec
Subject(s) Noise, hearing and vibration
Personal protection
Broad subject area(s) Physical hazards
Browse category(ies) Personal protection
Noise