The 70-year-old singer admits that he will go to extreme lengths to ensure no harm comes to his distinctive vocal cords, which means hours of no talking, which often confuses the youngest of his children.

Stewart tells Britain's Sunday Mirror newspaper, "I'm paranoid. I do voice rests. My kids wonder why I'm not talking. Mum has to tell them, 'Daddy can't talk right now, he's working'. My youngest must think dad's gone dumb. But it's my instrument, I look after it as if it were my crown jewels. As long as the voice is there I'll keep going, I've been lucky it's stayed in pretty good shape."

Stewart is married to former model Penny Lancaster.