The proton pack is the backpack energy weapon carried by the Ghostbusters in the 1984 film Ghostbusters, and its firing stream became one of the franchise's most recognisable sounds. Later films, cartoons, video games and fan edits kept the crackling beam in circulation, often using it as shorthand for high-tech ghost hunting. Because the noise is instantly associated with that world, creators still reach for it when they want a scene to feel both nostalgic and explosively powerful.