Threshold Shift in Hearing as a Function of Bandwidth and Mode of Noise Exposure

Details

• Personal Author:
  Cohen A ; Jackson E Jr.
• Description:
  A study was conducted comparing temporary threshold shifts (TTS) in hearing resulting from constant level, variable level, and intermittent exposure to three bandwidths of fatiguing sound. Subjects were exposed for 15 minutes to the three modes of whole octave band, 1/3 octave band centered at 1,000 hertz, and pure tone of 1,000 hertz fatiguing sound. The 1/3 octave band sound pressure levels (SPLs) were 5 decibels (dB) below the whole octave band levels and the pure tone SPLs were equal to the 1/3 octave band levels for one set of exposures and were 3dB lower in another set. All of the exposures to the three band widths of fatiguing sound in the three different modes resulted in TTS. The TTS produced for the 1/3 octave band exposures were smaller than those produced under whole octave band conditions suggesting that the National Academy of Science/National Research Council Committee on Hearing, Bioacoustics, and Biomechanics specification of a more stringent 1/3 octave band limit of 5dB relative to that of an octave band of the same center frequency errs on the conservative side. TTS in excess of those found for the 1/3 octave band condition were seen for pure tones equal in intensity to 1/3 octave band exposure levels. These findings were in disagreement with the idea that the critical band for TTS is about 1/3 octave in width. Equivalent TTS were seen for pure tone exposure levels 3dB below the 1/3 octave band intensity and for those produced by the 1/3 octave band exposures. Less TTS was produced by variable exposure than by constant exposure conditions, irrespective of bandwidth. The implications of these findings were discussed. [Description provided by NIOSH]
• Subjects:
  Hearing Noise Noise, Occupational Occupational Health Safety
• Keywords:
  Exposure-limits Hearing-threshold Humans Noise-analysis Noise-exposure Noise-frequencies Permissible-limits Steady-state-noise
• Publisher:
  Bureau of Occupational Safety and Health
• Document Type:
  Text
• Genre:
  Report
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-23
• NIOSHTIC Number:
  nn:00237813
• Citation:
  Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Consumer Protection and Environmental Health Service, Environmental Control Administration, Bureau of Occupational Safety and Health, RR-12, 1969 Feb; :1-23
• Federal Fiscal Year:
  1969
• Peer Reviewed:
  False
• Source Full Name:
  Bureau of Occupational Safety and Health
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e5765f122c058e52f183afeedb39ec8b986a074640e40e8f6f7d93bce968ad050db52d92914a7ca512ee9acebf4a029f24fbc8d9787c8144f6a117be692d07ca
• Download URL:
  https://stacks.cdc.gov/view/cdc/197895/cdc_197895_DS1.pdf
• File Type:
  [PDF - 15.46 MB ]