Many years ago I suffered from prolonged hoarseness of voice, and the ENT specialist I saw said I had "singers nodes". He put me on strict voice rest for two weeks, and I had to carry a magic slate around to communicate with. It was frustrating, but it worked. I have never had any trouble since. The doctor did tell me at the time if voice rest didn't work I would need to have surgery to remove the nodes. He said that the vocal cords vibrate with singing, etc., and this causes the nodes to develop (sort of like callouses).