I had met an accident in 1990, I had head injury and lot of blood from my left hear had drained out. After 2-3 months ent doctor had done audiometry and there was 20% hearing loss in left ear. I was suggested to have a surgical opening to sea the damage which I did not got done. Now after 30 years crom my left ear almost 95% from air conduction I can't hear. Can it be cured by medicine or operation.