Human Temporary Threshold Shift and Recovery from 24 Hour Acoustic Exposures

Abstract

The effects on hearing sensitivity of 24 hour monotic exposures to a narrow band noise with the center frequency at 1000 Hz at sound intensities of 80, 85, and 90 dB(A) were evaluated. Automatic audiometry was used to assess changes in hearing from baseline levels for six test frequencies during exposure and during subsequent recovery. Among the results (1) TTS (Temporary Threshold Shift) growth and recovery was present for 1000, 1500, and 2000 Hz test frequencies only, (2) TTS reached a maximum or asymptote between 8 and 16 hours exposure, (3) TTS induced by the 85 and 90 dB(A) exposure levels exceeded the limits specified by CHABA (Committee on Hearing, Bioacoustics and Biomechanics) damage risk criteria and (4) long duration exposures of 85 and 90 dB(A) require at least 24 hours of rest prior to subsequent exposure.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1975
Accession Number
ADA007842

Entities

People

  • Charles W. Nixon
  • Daniel L Johnson
  • David W. Krantz

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Acoustics
  • Air Force
  • Air Force Facilities
  • Air Force Personnel
  • Anechoic Chambers
  • Background Noise
  • Biomedical Research
  • Ear
  • Frequency
  • Government Procurement
  • Governments
  • Loudspeakers
  • Measurement
  • Microphones
  • Military Aircraft
  • Noise
  • Procurement

Readers

  • Acoustics.
  • Auditory Neuroscience/Auditory Physiology.