I've Had An Ear Operation Before And The Doctors Put

I've had an ear operation before and the doctors put something white in my ears (like a little white ball or somehting close). This was when I was really young. The one which was ut into my left ear came out, but the one in my right ear is still inside and my hearing is slightly muffled in my right ear. I've had doctors check it and remove the wax, but it's still blocked. Do you know what may be wrong?