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Document ID (ISN)37610
CIS number 82-675
ISSN - Serial title 0002-8894 - American Industrial Hygiene Association Journal
Year 1981
Convention or series no.
Author(s) Behar A.
Title Attenuation of hearing protectors and the NRR factor
Bibliographic information Dec. 1981, Vol.42, No.12, p.904-908. 7 ref.
Abstract The estimated dBA levels at the protected ear were calculated using the ISO-NIOSH method and the Noise Reduction Rating factor (NRR) adopted by the EPA (US Environmental Protection Agency). The dBA level of the protected ear is predicted by subtracting the NRR from the noise level measured as dBC. The sound level was predicted by each method for 144 combinations of 12 noises and 12 protectors. The level predicted using NRR was always higher than measured with a difference range of 0-11.3dBA. Because of this conservative estimation of attenuation and the simplicity of use, the application of the NRR in hearing conservation programmes is recommended.
Descriptors (primary) hearing protection; prediction formulae; sound attenuation; noise
Descriptors (secondary) sound absorption; audiometric tests; noise level measurement
Document type D - Periodical articles
Subject(s) Noise, hearing and vibration
Broad subject area(s)
Browse category(ies) Noise
Hearing protection