Hearing protector labeling for active noise reduction devices.

Details

• Personal Author:
  Behar A ; Franks, John R. ; Murphy, William J.
• Description:
  The US EPA regulation 40 CFR part 211b does not specify how to label hearing protectors that use active noise reduction(ANR). Real-ear attenuation at threshold (REAT) measurements are appropriate for testing the passive noise reduction performance of the earmuff. The contribution of ANR to the overall attenuation must be measured either with an acoustic test fixture (ATF) or using the microphone in real ear (MIRE) technique. ATFs must adequately mimic the coupling of the protector with either the skin of the ear canal or the side of the head, as well as provide sufficient attenuation to eliminate effects of bone conduction. The MIRE technique uses a miniature microphone positioned in the ear canal either at the entrance or at the tympanic membrane, and can be used to measure the insertion loss between the occluded and unoccluded conditions for both the passive and active modes of the protector. ATF and MIRE measurements made for several protectors demonstrate effective performance below 1000 Hz. This paper will examine methods for combining ATF and MIRE measurements with REAT to develop effective and informative rating for the ANR class of hearing protectors. [Description provided by NIOSH]
• Subjects:
  Acoustics Ear Laboratories Noise Noise, Occupational Occupational Health Personal Protective Equipment Protective Clothing Safety Sense Organs
• Keywords:
  Laboratory-testing; Impulse-noise; Acoustical-materials; Acoustical-measurements; Acoustics; Shock-waves; Sound; Sound-analyzers; Sound-propagation; Ear-protection; Ear-protectors; Hearing-protection; Noise-analysis; Noise-levels; Noise-sources
• ISSN:
  0001-4966
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Alabama ; Indiana ; Ohio ; OSHA Region 4 ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DART - Division of Applied Research and Technology
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  116
• Issue:
  4
• NIOSHTIC Number:
  nn:20045254
• Citation:
  J Acoust Soc Am 2004 Oct; 116(4):2595
• Contact Point Address:
  William J. Murphy, Hearing Loss Prevention Team, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 1090 Tusculum Ave., Mailstop C-27, Cincinnati, OH 45226-1998
• Email:
  wjm4@cdc.gov
• Federal Fiscal Year:
  2005
• Peer Reviewed:
  False
• Source Full Name:
  Journal of the Acoustical Society of America
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7dc847c09aedf140bc731323e8446b4703641ae07d6ad9e7b7238120dab30b8f7dcaa9b938d34d035f87873a0fe7fec262d5d13dcaf290925445e82b6de3b57d
• Download URL:
  https://stacks.cdc.gov/view/cdc/248268/cdc_248268_DS1.pdf
• File Type:
  [PDF - 168.02 KB ]