Four Earplugs in Search of a Rating System

Details

• Personal Author:
  Franks, John R. ; Harris DA ; Johnson, James S. ; Murphy, William J.
• Description:
  The performance of four insert earplugs was evaluated by determining the Noise Reduction Rating (NRR) and the Subject-Fit Noise Reduction Rating [NRR(SF)]. The NRR and NRR(SF) were calculated from real-ear attenuation at threshold (REAT) data collected using the experimenter-fit protocol described in the now-rescinded ANSI S3.19-1974 (American National Standards Institute, 1974) and the subject-fit protocol of the recently revised ANSI S12.6-1997 (American National Standards Institute, 1997) standards for REAT measurement. A comparison of the experimenter-fit and subject-fit REAT performance was conducted using four pools of subjects, one pool per protector. Each device was tested with at least 20 subjects, the minimum size necessary to estimate the NRR(SF) for an earplug. The REAT was measured with third-octave narrowband noise stimuli for center frequencies at 0.125, 0.25,0.5, 1, 2, 3.15, 4, 6.3, and 8 kHz. The REAT means and standard deviations were compared with the manufacturer data. This study showed that the NRR(SF) is typically lower than the NRR and that the NRR(SF) is not well-predicted by the NRR derating schemes recommended by the National Institute for Occupational Safety and Health and required by the Occupational Safety and Health Administration. The difference between the present NRR on hearing protector labels and the NRR(SF) is sufficiently large and unpredictable enough to render the application of derating schemes meaningless even though these schemes attempt to account for the difference between the laboratory and real-world outcomes. The only way to provide a protector noise rating that is predictive of a real-world outcome is to retest the protector according to the subject-fit method of ANSI S12.6-1997 (American National Standards Institute, 1997). [Description provided by NIOSH]
• Subjects:
  Ear Environmental Exposure Hearing Hearing Loss Hearing Loss, Noise-Induced Noise Noise, Occupational Occupational Health Protective Clothing Safety Sense Organs

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• Keywords:
  Ear Protection Ear Protectors Exposure Levels Hearing Disorders Hearing Loss Hearing Protection Noise Absorption Noise Control Noise Exposure Noise Protection
• ISSN:
  0196-0202
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 5 ; OSHA Region 6 ; Texas
• 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:
  218-226
• Volume:
  21
• Issue:
  3
• NIOSHTIC Number:
  nn:20020673
• Citation:
  Ear Hear 2000 Jun; 21(3):218-226
• Federal Fiscal Year:
  2000
• Peer Reviewed:
  True
• Source Full Name:
  Ear and Hearing
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f94334d74d6bb080db3722cc0637781edbf4d1cc553cb411594815178cd613cbe85dd4e38d1de37a3089842f00493605bed58abda5808532e67471bf0b63ed7f
• Download URL:
  https://stacks.cdc.gov/view/cdc/198354/cdc_198354_DS1.pdf
• File Type:
  [PDF - 994.99 KB ]