Air horns are loud, attention-grabbing devices that produce a strong sound when compressed air is released. They are commonly used in sports events, celebrations, and emergencies to signal or alert people. The sound is created by forcing air through a narrow opening, which amplifies the noise. Typically made of metal or plastic, air horns come in various sizes and designs. They can be handheld or mounted on vehicles like boats and trucks. Many air horns are refillable, allowing users to replace the compressed air when it runs out, making them a popular choice for repeated use in events or safety situations.