Protecting hearing from impulsive noise

Details

• Personal Author:
  Murphy, William J.
• Description:
  Impulse and impact noises pose a significant risk to the unprotected ear. Workers in manufacturing and construction use tools that can easily generate momentary exposure in excess of 130 decibels peak sound pressure level (dB peak SPL). Persons that use small caliber firearms (e.g., law enforcement, security personnel, military, hunters, and shooters) experience levels anywhere from 140 to 175 dB peak SPL. In the military, large caliber weapons produce impulse noise levels that can be as intense as 185 to over 190 dB peak SPL. As a consequence of high-level impulse and impact noise exposure, the prevalence of hearing loss is greater for persons in these occupations and using these types of equipment (Masterson et al., 2014; Fausti et al., 2005). In the early history of hearing conservation, the military conducted investigations of the effectiveness of a hearing protection device using weapon noise. In 2009, the EPA proposed a measurement method to capture the impulse peak insertion loss (IPIL) of a protector. Impulses are generated at three levels: 132, 150 and 168 dB peak SPL. The source of the impulse can be an explosive, a small-caliber weapon or an acoustic shock tube. The EPA's method served as the basis to update the ANSI S12.42 standard in 2010 (ANSI/ASA, 2010). The ANSI/ASA S12.42-2010 standard has proven useful to characterize hearing protector performance. The ANSI S12 Working Group 11 responsible to update the standard has been considering other improvements to the measurements. First and foremost, the working group needs to understand effects of the spectral difference on the IPIL results. Second, while the acoustic shock tube produces well-developed shock waves for levels above 140 to 150 dB, the generation of impulses at 130 to 140 dB needs further investigation. Finally, the problem of accounting for bone conduction has not been addressed well (Clavier et al., 2012; Murphy et al, 2015). NIOSH and 3M scientists have tried some preliminary approaches; however, future methods must consider the frequency-dependent nature of the bone-conduction pathways. [Description provided by NIOSH]
• Subjects:
  Ear Hearing Hearing Loss, Noise-Induced Musculoskeletal System Noise Noise, Occupational Occupational Health Personal Protective Equipment Protective Clothing Quality Control Safety Sense Organs

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• Keywords:
  Acoustical-materials Acoustics Bone-structure Ear-protection Ear-protectors Ears Equipment-design Equipment-reliability Exposure-levels Hearing-conservation Hearing-protection Impact-noise Impulsive Noise Noise-absorption Noise-exposure Noise-frequencies Noise-induced-hearing-loss Noise-measurement Noise-propagation Noise-protection Noise-sources Performance-capability Quality-standards Standards

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• ISSN:
  1083-7388
• Publisher:
  National Hearing Conservation Association
• Document Type:
  Text
• Genre:
  Newsletter
• Place as Subject:
  Colorado ; Ohio ; OSHA Region 5 ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DART - Division of Applied Research and Technology
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  15-18
• Volume:
  32
• Issue:
  2
• NIOSHTIC Number:
  nn:20047260
• Citation:
  Spectrum 2015 Nov; 32(2):15-18
• Contact Point Address:
  William J. Murphy, Hearing Loss Prevention Team, National Institute for Occupational Safety and Health, 1090 Tusculum Ave., Mailstop C-27, Cincinnati, OH 45226-1998
• Email:
  Wjm4@cdc.gov
• Federal Fiscal Year:
  2016
• NORA Priority Area:
  Manufacturing ; Public Safety
• Peer Reviewed:
  False
• Source Full Name:
  Spectrum: the National Hearing Conservation Association newsletter
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a82904a98cade6c4445b709ec220320f3a0b6fc506f1c96e3627a36000cc83e986984209a1410cd2523f7de5ad5c9df5ad5f1829c492f899ad9c16efa3972810
• Download URL:
  https://stacks.cdc.gov/view/cdc/202401/cdc_202401_DS1.pdf
• File Type:
  [PDF - 1.54 MB ]