This type of mortar sound is a generic military effect rather than a line from a single film or game, built around the familiar whistle of an incoming shell followed by a distant blast. Similar effects have long been used in war footage, games and action edits to warn of an attack without showing a full explosion. Online, the short clip has found a second life in memes and short-form videos, where the whistle alone is enough to tell viewers that trouble is about to arrive.