Air horn
Encyclopedia
The air horn is a device designed to create an extremely loud noise. It is usually composed of a pressurized air source coupled to a horn
through a valve
which allows the device to be turned on and off. Air horns have been installed on large semi-trailer truck
s, fire trucks
, and some ambulance
s for many years. It is also used on trains as a warning device, and on ships as a signalling device.
system. A cord mounted on the ceiling of the operator's cab is pulled to open the valve, supplying varying amounts of air to the horn. Thus, an outstretched hand reaching upward and pumping is a signal to the driver of an air horn equipped vehicle, requesting a toot. In modern trucks the horn is actuated by a button on the steering wheel (just like a normal car horn). Some trucks have both electric and air horn, selectable by a switch on the dashboard. This is to prevent the use of the powerful air horn in populated areas.
There are also electronic horns for emergency vehicles, which produce a similar easily-recognizable sound. These are typically integrated into the same system as the vehicle's electronic siren, and sound through the same speakers. In the last several decades, electronic sound systems with more widely varying frequencies have been chosen as common supplemental warning systems.
Original diesel locomotives were equipped with truck horns. After an accident in which a driver
mistook a train for a truck, the need for a unique train horn became clear http://utubc.com/meeting/meeting30.htm. Consequently, North American trains now have at least two "horns" forming the airhorn, that sound simultaneously, creating a chord. Three and five-tone configurations are the most common, but two-tone configurations also exist http://www.dieselairhorns.com/collection.html. At a grade crossing, the usual sequence is two longs, one short, and one long, except in locations where airhorns are not allowed to sound because of quiet zone ordinances.
In recent years it has become a fad for car and truck enthusiasts to install large air horns on their vehicles. The use of a train horn in an automobile could cause an accident. Some jurisdictions do not even allow an airhorn to be attached, whether or not it can be activated.
and indoor soccer
. There are normally two horns; a small high one that announces the end of the period, and a much louder, lower horn that is sounded when the home team scores and/or wins the hockey game. Some air horns are used for signaling the end of the period or quarter on scoreboard systems. In mixed martial arts
an air horn is commonly used to signal the end of a round as opposed to the bell used in boxing
and professional wrestling
. For outdoor activities like hiking, hunting, cross country skiing, canoeing, fishing, and etc. an air horn can be handy to scare off unwanted or aggressive wild life and as well for signalling help and location.
air horns are also readily available packaged with a can of compressed air as the air source. These are often sounded by fans at sporting events such as American football
, basketball
, hockey
and association football, and at other outdoor events. Small versions are sometimes used as bicycle horns or non-lethal weapons for self-defense, mainly as an auditory
distraction to get away from an attacker. At close range, they can also be used as freeze sprays (when the container is held upside-down).
The reason an air horn can function as an effective refrigerant
is that the gases contained within the device are highly pressurized, which means that the object also acts as a pressure vessel
.
Additionally, air horns (especially those that contain fluorocarbons) have the potential to be used as recreational drugs since many such refrigerants can be inhaled
for a quick and dangerous intoxication.
television series and movies, air horns are occasionally used to frighten people.
A popular web series called "Terror On The Streets" depicts drivers of such vehicles startling unsuspecting pedestrians while driving through urban areas http://video.google.com/videosearch?q=terror+on+the+streets. Many people amuse themselves by driving around blasting air horns at others, or using them in other ways. Youtube
has many videos about such events. A common undertaking with the air horn is the accordingly named "golf course air horn", where pranksters blow an airhorn just as an unsuspecting golfer is coming down with their swing.
The airhorn is also a popular sample in reggae music. Jamaican dancehall music was the first musical genre to use the effect, and has been using the airhorn sample for over 26 years, in live shows as well as on mixtape recordings. The effect has recently been used in hiphop music as well as reggaeton
, a reggae hybrid genre.
Horn (acoustic)
A horn is a tapered sound guide designed to provide an acoustic impedance match between a sound source and free air. This has the effect of maximizing the efficiency with which sound waves from the particular source are transferred to the air...
through a valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...
which allows the device to be turned on and off. Air horns have been installed on large semi-trailer truck
Semi-trailer truck
A semi-trailer truck, also known as a semi, tractor-trailer, or articulated truck or articulated lorry, is an articulated vehicle consisting of a towing engine , and a semi-trailer A semi-trailer truck, also known as a semi, tractor-trailer, or (in the United Kingdom and Ireland) articulated truck...
s, fire trucks
Fire apparatus
A fire apparatus, fire engine, fire truck, or fire appliance is a vehicle designed to assist in fighting fires by transporting firefighters to the scene and providing them with access to the fire, along with water or other equipment...
, and some ambulance
Ambulance
An ambulance is a vehicle for transportation of sick or injured people to, from or between places of treatment for an illness or injury, and in some instances will also provide out of hospital medical care to the patient...
s for many years. It is also used on trains as a warning device, and on ships as a signalling device.
Trucks
A true air horn is piped into a heavy vehicle's compressed air brakeAir brake (road vehicle)
Air brakes are used in trucks, buses, trailers, and semi-trailers. George Westinghouse first developed air brakes for use in railway service. He patented a safer air brake on March 5, 1872. Originally designed and built for use on railroad train application, air brakes remain the exclusive systems...
system. A cord mounted on the ceiling of the operator's cab is pulled to open the valve, supplying varying amounts of air to the horn. Thus, an outstretched hand reaching upward and pumping is a signal to the driver of an air horn equipped vehicle, requesting a toot. In modern trucks the horn is actuated by a button on the steering wheel (just like a normal car horn). Some trucks have both electric and air horn, selectable by a switch on the dashboard. This is to prevent the use of the powerful air horn in populated areas.
Emergency vehicles
Many fire trucks, ambulances, and other large emergency vehicles operate air horns as a means of warning vehicles to clear the right-of-way. These may include traditional truck-style air horns, or stuttertone air horns, which produce an easily recognizable tone. Many US firetrucks have stuttertone air horns installed.There are also electronic horns for emergency vehicles, which produce a similar easily-recognizable sound. These are typically integrated into the same system as the vehicle's electronic siren, and sound through the same speakers. In the last several decades, electronic sound systems with more widely varying frequencies have been chosen as common supplemental warning systems.
Train locomotives
mistook a train for a truck, the need for a unique train horn became clear http://utubc.com/meeting/meeting30.htm. Consequently, North American trains now have at least two "horns" forming the airhorn, that sound simultaneously, creating a chord. Three and five-tone configurations are the most common, but two-tone configurations also exist http://www.dieselairhorns.com/collection.html. At a grade crossing, the usual sequence is two longs, one short, and one long, except in locations where airhorns are not allowed to sound because of quiet zone ordinances.
In recent years it has become a fad for car and truck enthusiasts to install large air horns on their vehicles. The use of a train horn in an automobile could cause an accident. Some jurisdictions do not even allow an airhorn to be attached, whether or not it can be activated.
Sports
The air horn is used for signalling in ice hockey (especially in the NHL), as well as in the NLLNational Lacrosse League
The National Lacrosse League is a men's professional indoor lacrosse league in North America. It currently has nine teams; three in Canada and six in the United States. Unlike other lacrosse leagues which play in the summer, the NLL plays its games in the winter and spring. Each year, the playoff...
and indoor soccer
Indoor soccer
Indoor soccer or arena soccer, or six-a-side football in the United Kingdom, is a game derived from association football adapted for play in an indoor arena such as a turf-covered hockey arena or skating rink. The most important difference in play is that the indoor field is surrounded by a wall...
. There are normally two horns; a small high one that announces the end of the period, and a much louder, lower horn that is sounded when the home team scores and/or wins the hockey game. Some air horns are used for signaling the end of the period or quarter on scoreboard systems. In mixed martial arts
Mixed martial arts
Mixed Martial Arts is a full contact combat sport that allows the use of both striking and grappling techniques, both standing and on the ground, including boxing, wrestling, Brazilian jiu-jitsu, muay Thai, kickboxing, karate, judo and other styles. The roots of modern mixed martial arts can be...
an air horn is commonly used to signal the end of a round as opposed to the bell used in boxing
Boxing
Boxing, also called pugilism, is a combat sport in which two people fight each other using their fists. Boxing is supervised by a referee over a series of between one to three minute intervals called rounds...
and professional wrestling
Professional wrestling
Professional wrestling is a mode of spectacle, combining athletics and theatrical performance.Roland Barthes, "The World of Wrestling", Mythologies, 1957 It takes the form of events, held by touring companies, which mimic a title match combat sport...
. For outdoor activities like hiking, hunting, cross country skiing, canoeing, fishing, and etc. an air horn can be handy to scare off unwanted or aggressive wild life and as well for signalling help and location.
Portable or personal air horns
PortablePortable
Portable may refer to:* Portable building, a manufactured structure that is built off site and moved in upon completion of site and utility work...
air horns are also readily available packaged with a can of compressed air as the air source. These are often sounded by fans at sporting events such as American football
American football
American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...
, basketball
Basketball
Basketball is a team sport in which two teams of five players try to score points by throwing or "shooting" a ball through the top of a basketball hoop while following a set of rules...
, hockey
Hockey
Hockey is a family of sports in which two teams play against each other by trying to maneuver a ball or a puck into the opponent's goal using a hockey stick.-Etymology:...
and association football, and at other outdoor events. Small versions are sometimes used as bicycle horns or non-lethal weapons for self-defense, mainly as an auditory
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
distraction to get away from an attacker. At close range, they can also be used as freeze sprays (when the container is held upside-down).
The reason an air horn can function as an effective refrigerant
Refrigerant
A refrigerant is a substance used in a heat cycle usually including, for enhanced efficiency, a reversible phase change from a liquid to a gas. Traditionally, fluorocarbons, especially chlorofluorocarbons, were used as refrigerants, but they are being phased out because of their ozone depletion...
is that the gases contained within the device are highly pressurized, which means that the object also acts as a pressure vessel
Pressure vessel
A pressure vessel is a closed container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.The pressure differential is dangerous and many fatal accidents have occurred in the history of their development and operation. Consequently, their design,...
.
Additionally, air horns (especially those that contain fluorocarbons) have the potential to be used as recreational drugs since many such refrigerants can be inhaled
Inhalation
Inhalation is the movement of air from the external environment, through the air ways, and into the alveoli....
for a quick and dangerous intoxication.
Popular culture
Air horns have been used as jokes, and running gags in cartoons and movies. In the JackassJackass (TV series)
jackass is an American reality series, originally shown on MTV from 2000 to 2002, featuring people performing various dangerous, crude, ridiculous, self-injuring stunts and pranks...
television series and movies, air horns are occasionally used to frighten people.
A popular web series called "Terror On The Streets" depicts drivers of such vehicles startling unsuspecting pedestrians while driving through urban areas http://video.google.com/videosearch?q=terror+on+the+streets. Many people amuse themselves by driving around blasting air horns at others, or using them in other ways. Youtube
YouTube
YouTube is a video-sharing website, created by three former PayPal employees in February 2005, on which users can upload, view and share videos....
has many videos about such events. A common undertaking with the air horn is the accordingly named "golf course air horn", where pranksters blow an airhorn just as an unsuspecting golfer is coming down with their swing.
The airhorn is also a popular sample in reggae music. Jamaican dancehall music was the first musical genre to use the effect, and has been using the airhorn sample for over 26 years, in live shows as well as on mixtape recordings. The effect has recently been used in hiphop music as well as reggaeton
Reggaeton
Reggaeton is a form of Puerto Rican and Latin American urban and Caribbean music. After its mainstream exposure in 2004, it spread to North American, European and Asian audiences. Reggaeton originated in Puerto Rico but is also has roots from Reggae en Español from Panama and Puerto Rico and...
, a reggae hybrid genre.