Air horns began as signaling devices using compressed air, long used on boats, trucks and at sporting events to get attention over crowd noise. Online, the blast became a staple of prank videos and early 2010s montage parodies, where rapid horn hits were layered over trick shots and celebrations, a style closely tied to the MLG air horn meme. That exaggerated use turned a practical warning sound into a comedy cue, and the short solo blast still works today for startles, fake celebrations and abrupt edits.