A Klaxon is a type of electric horn which emits a particularly loud and penetrating sound. The word Klaxon is technically a brand trademark, although the word is used generically to describe any sort of loud wailing noise which attracts attention, and the Klaxon company still makes alert mechanisms, horns, and safety equipment. The classic “ahooga” emitted by a Klaxon is familiar to viewers of submarine movies and fans of early twentieth century cars, both of which installed Klaxons to serve as part of their emergency systems.
The design of a Klaxon includes a horn attached to a diaphragm with a small rivet in the center which is repeatedly struck by a wheel when the Klaxon is activated. The horn amplifies and directs the noise, creating a concentrated field of sound which is audible at a considerable distance, especially if the horn is large. A motor drives the apparatus, and can either be hand cranked or attached to batteries. Even a small Klaxon can be quite noisy, and larger models can be deafening to someone in close proximity.
The original Klaxon was developed in the early twentieth century, and the design was purchased by the New Jersey based Lovell-McConnell manufacturing company in 1908. The company also came up with the “Klaxon” name, derived from the Greek klazo, to shriek, and Klaxons appeared on cars and bicycles in the same year. Several militaries adopted the Klaxon for use as an evacuation and general alert alarm, and they continue to be used for this purpose. The Klaxon is also widely used in Hollywood films, particularly when a headquarters needs to be evacuated.
On the road, the Klaxon has largely been replaced with less aggressive sounding automobile horns, and drivers associate the noise with venerable cars. A traditional Klaxon for automotive use could, however, be fitted to essentially any vehicle with an electrical horn system, and some drivers do add Klaxons to their modern vehicles for special occasions. In the military, the Klaxon is widely used, and many large buildings include the sounding of Klaxons in their evacuation procedures, as people associate the noise with urgency.
As a general rule, horns of any sort should only be sounded in an emergency situation, to prevent confusion. Whether on a ship, car, or bicycle, a horn should be used to attract the attention of someone who does not appear to be focusing, or to indicate that immediate movement out of the area is advised. Use of a horn for frivolous purposes detracts from its value as a safety mechanism.