Employee stated that he was laying on his left side using a cutting torch to cut out bogie pins on dozer roller frame. A piece of metal slag popped off and into his right ear. To ER doctor-burn, ear drops. To comp doctor on 12/6 & 12/13 - puncture ear drum. To ENT doctor on 12/16-same diagnosis. Talked to MSHA/Denver 12/22 and report as first aid case per them. No lost time.