An air horn is a compact yet powerful pneumatic noisemaker that generates a piercing, high-volume blast by releasing compressed air through a vibrating diaphragm and flared horn—commonly reaching up to about 115 dB or more. It’s widely used as a safety and signaling tool across many settings—from emergency vehicles, boats, and construction zones to sporting events and outdoor adventures—thanks to its ability to grab attention instantly and carry sound over long distances (even up to half a mile). Despite its simplistic design, the air horn remains one of the most effective forms of loud audible alerts for both practical and celebratory uses.