Mobile Phone Annoying Noise

[kicks66]

some people at my school have been playing this noise from their mobiles, its starts of really high pitched, then goes down for a while then back up again, its so high you cant tell where its coming from, does anyone know where i can find it?

 

[Mackass]

I think I've got what you're looking for - does it sound like one of those old fashioned kettles, the ones that make that high pitch when hot?