How can I improve my CD sound?

Anyone out there know the secret as to why I can't listen to cd's on any of my players I've tried or anyone elses either? What is interesting is that I can listen to FM, which is mostly CD's and I don't get the ear pain I get from mine. Why not a bother? Don't give me any easy answers. I've tried them more that likely. I've spoken to the engineers at many radio stations and they all tell me that they are not placing any "correction" electronics at their stations. Got to be an answer to this. Love to be able to to listen to them. Thanks, you guys!.