The `All I Wanna Do` singer said during her 20 years as a singer her voice has grown in many ways, but the thing which impresses her guitar player -Doyle Bramhall II - most, is her ability to sing through a case of wind.
She told popeater.com: "Doug just thinks it`s fascinating that I can sing through a burp if that means anything to you.
"I can be onstage and, you know, I can sustain a burp until I`m done with a phrase. You know part of it is just doing it, part of it is singing, it`s like any other sort of craft of muscle.
"The more you do it, hopefully, the better you get at it, the more you understand it and the better you are able to control."
While Sheryl - who was a backing vocalist for Michael Jackson before becoming a solo artist - has grown as a vocalist, she looks up to the way a legendary musician like folk singer Bob Dylan is always learning and improving at his craft.
She added: "Bob Dylan`s a great example of someone who didn`t want to stay static. He did a very big event in Tokyo with Joni Mitchell and took voice lessons for it. So I think good singers and singers who are very alive in their art continue to work at it."