30 CFR §62.171

 Audiometric test procedures

(a) All audiometric testing under this part must be conducted in accordance with scientifically validated procedures. Audiometric tests must be pure tone, air conduction, hearing threshold examinations, with test frequencies including 500, 1000, 2000, 3000, 4000, and 6000 Hz. Each ear must be tested separately.

(b) The mine operator must compile an audiometric test record for each miner tested. The record must include:

(1) name and job classification of the miner tested;
(2) a copy of all of the miner's audiograms conducted under this part;
(3) evidence that the audiograms were conducted in accordance with paragraph (a) of this section;
(4) any exposure determination for the miner conducted in accordance with § 62.110 of this part; and
(5) the results of follow-up examination(s), if any.