that should not be a problem then its fairly new, have u changed anything around, check your control panel and look into sounds in there, for your sound card config, or if you have realtek or some type of sound enhance software that came with the comptuer check if that is off.
Trina, If you've recently updated your Sound Card drivers, Try doing a driver rollback. If you haven't, Try updating the drivers to the latest version from the manufacturers website.