I've always heard it called "Doink Doink." But the official name for it is apparently The Ching: Mike Post: ...(Dick Wolf) said I need a sound that goes along with these cards that are going to identify our location.
Q: The chunk, chunk sound.
Post: Right. And those could happen every 2 minutes, every 4 minutes, it's going to happen a lot in the show. So I went and sampled -- I found a sample of a jail door closing, and I put it with a couple of little other sounds, and made this ching-ching thing.