30 C.F.R. § 62.160
(a) A mine operator must provide a hearing protector to a miner whose noise exposure equals or exceeds the action level under § 62.120 of this part. In addition, the mine operator must:
(c) The mine operator must ensure, after satisfying the requirements of paragraph (a) of this section, that a miner wears a hearing protector when the miner's noise exposure is at or above the action level, if: