hi Lisa, sounds like it might be the drive belt thats become detatched from the drum, what you're hearing is probably just the fan. If the dryer is in warranty get it fixed free of charge. If not it should be just a case of removing the outer case and slipping a new belt on (always disconnect the power supply), if you have no experience in domestic appliances I would recommend you call an authorised repair man.
Regards
Dave.
Dave Sparky, May 2006