|Document ID (ISN)||109244|
|ISSN - Serial title
||0007-9952 - Cahiers de notes documentaires - Hygiène et sécurité du travail
|Convention or series no.
||INRS ND 2295-212-08
||In-situ attenuation of hearing protection devices - Literature survey
||Affaiblissement acoustique in situ des protecteurs individuels contre le bruit - Étude bibliographique [in French]|
||3rd Quarter 2008, No.212, p.-43-59. Illus. 60 ref.
||http://www.hst.fr/inrs-pub/inrs01.nsf/IntranetObject-accesParReference/HST_ND%202295/$File/nd2295.pdf [in French]
||Directive 2003/10/EC (see CIS 06-253) has modified European regulations on protecting workers against noise exposure. This directive specifically introduces a new requirement in the form of exposure limit values, the level of daily noise exposure being henceforth limited to 87dB(A) and peak sound pressure level to 140dB(C), including attenuation of hearing protectors. Exposure level determination requires knowing both the sound pressure spectrum for the exposure noise and the noise attenuation values of hearing protection devices (HPD) based on their field estimation. These constraints lead to difficulties of both metrological and methodological nature. The aim of this literature survey was to establish the current state of the art in relation to the real capacity of HPD to attenuate noises. Testing methods applied to determining HPD noise attenuation are described. The survey reveals a major difference between attenuation values declared in HPD manufacturers' specifications and real attenuation values measured in situ. Moreover, this difference varies, depending on the HPD type, ranging from 5dB for safety helmet-mounted ear-muff types to nearly 22dB for formable foam ear-plug types. There are insufficient data on custom-moulded ear-plug type and additional investigations are required in this area.
||hearing protection; sound attenuation; limitation of exposure
||literature survey; threshold limit values; European Union; earplugs; comment on standard; noise dosimetry; equipment testing; comment on directive; earmuffs
||D - Periodical articles
|Country / State or Province||France|
||Noise, hearing and vibration
|Broad subject area(s)