Dr. Ahmad Latif is a physician, web editor and author with a special interest in workplace health promotion.

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The noise exposure calculator is based on OSHA criteria.

OSHA's maximum allowable daily 8-hour TWA with protection is 90 dBA or 100% noise dose.

TWA: Time-weighted Average
Noise Exposure
H : M
Exposure Time



  • Noise Exposure or Sound Level: The average sound level measured for the worker at this location.
  • Duration or Exposure Time: The length of time that the worker spends at this location each day.
  • 8-Hour Time-Weighted Average: Average noise exposure figured for an 8-hour period.
  • Permissible Exposure Level (PEL): Maximum allowable 8-hour TWA noise exposure (OSHA's limit is 90 dBA).
  • Noise Dose: Percent of PEL to which worker exposed. 90 dBA 8-hour TWA equals a dose of 100%. An 85 dBA 8-hour TWA equals 50%. The exchange rate is used to figure this.
  • Exchange Rate: Amount of dBA at which noise dose doubles. OSHA uses a 5 dBA exchange rate which means that a worker exposed to 95 dBA receives twice the dose of 90 dBA.
  • Noise dosimeters: Devices used in sound surveys to calculate noise exposure.

Developed by: fittowork.net