Imagine your friends' reaction when at your next Sunday night no-holds-barred karaoke jam you not only perform a rockin' rendition of Ozzy's "Crazy Train," but you kick it out gripping a mic autographed by the self-proclaimed prince of darkness himself. Now that's the stuff of which local legends are made.

An array of artists including Osbourne, 'NSYNC, Christina Aguilera, the Dave Matthews Band and Moby have signed on to contribute their John Hancocks to the "Shure Bid for Hearing," a charity auction beginning April 29 on eBay which will feature microphones autographed by various musicians. Nelly Furtado, AC/DC, Hank Williams Jr. and the

Pretenders' Chrissie Hynde are also among the 20-plus musicians set to offer their signatures.

The auction is being held to help promote Better Hearing and Speech Month, and to raise money for the nonprofit hearing conservation organization House Ear Institute (HEI).