Employee had his annual HCI hearing test here at the Plant on 4/26/12. The results showed a STS had occurred and that the STS met the criteria for a recordable shift on Form 300. We sent him for a retest to our company doctor on 10/2/12. We did not know that this needed to be filled out on 7000-1. This was informed to us on 11/7/12 during a MSHA Plant Inspection.