Rocker Tom Keifer spends hours each day training his voice after he was diagnosed with vocal cord paralysis in the early 1990s.

The Cinderella frontman was told by doctors he had paresis - the inability for one or both of the vocal cords to move due to abnormal nerve input - but he refused to take the news and consulted several experts.

However, Keifer eventually accepted the diagnosis, and now works on maintaining his voice daily.

He tells California's Pasadena Star-News, "The onset of the problems was pretty sudden, almost overnight... My voice just started breaking and cracking, more in the middle register of my voice, and I couldn't control the notes.

"(A physician) did some other tests and he looked down my throat and then we had the big scary talk where he came in and said, 'The good news is you're not crazy, there is something wrong with your voice, but the bad news is it's a paresis, which is a fancy medical term for partially paralysed'.

"I finally just accepted that fact that that's what it was. I worked with coaches and built the strength back. Still to this day I have to work at it. I do a couple hours of therapy every day to keep the muscles and everything trained in there. It's not something that you're ever cured of or that you're ever across the goal line. It's a struggle every day."

Keifer has undergone six operations on his throat over the years to fix "collateral damage", but he refuses to be downbeat about the condition.

He adds, "One of the positive things that came out of this whole mess is that from the voice training I learned a lot of things and developed different areas of my voice. The middle part of my voice in particular, it's probably a little stronger than it used to be, although it's still volatile from day to day. But on a good day I can do things that maybe I couldn't do before this."