Toshiba Satellite Screen Hiss

My two year old Toshiba Satellite just started making a nasty, loud hissing noise from the base of the screen. It's always made a faint buzz from that area, even when it was new, but just yesterday that drastically accelerated from a slight buzz to a very loud noise that sounds like a mixture of grinding and hissing. It's much worse when cold, and gets louder on pages with a light colored background. The noise fades away when I press on the base of the screen. Is my screen about to take a dump? I haven't noticed any display issues (i.e. flickering or blotching).