A Geiger Counter is a device used to measure levels of radioactivity. When it picks up radioactivity, it creates a kind of "crackling" noise like this http://www.youtube.com/watch?v=qbSBWQc8YKg
I've seen(rather heard) this noise used to represent radioactivity or toxic waste in movies, tv, and videogames, I've heard it pretty much everywhere.
one example I can think of is in Psychonauts. If you roll over some Green bubbling goo on your levitation ball, it produces this noise.
Seen it a Million Times, etc. It's commonly used as laboratory-setting background. Could anyone help me out and add some examples?