MSHA Regulations

Hearing Testing

Summary of MSHA Rules

MSHA rules are largely the same as the OSHA rules with the following notable exceptions:


The mine operator is obliged to offer miners the opportunity for audiometric testing. Minersí participation is voluntary.

The mine operator must receive the results of testing within 30 days from the date the audiogram was conducted.

Dual Hearing Protection Level

The mine operator must ensure that a miner exposed to an 8-hour TWA of 105 or more wears both plugs and muffs.


The mine operator must provide hearing conservation training to a worker within 30 days of employment.


The mine operator must notify a worker of an STS or Reportable within 10 working days of receiving the results of testing.

A mine operator may conduct one retest of a test with a shift within 30 days of receiving the test results.


An employee is considered reportable when that employee has an average change of 25 dB or more in the 2000, 3000, and 4000 Hz frequencies of either ear from the baseline. The thresholds may be age adjusted.


The mine operator must keep audiometric test records for the duration of a minerís employment plus six months.

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