Vehicle horn - AbsoluteAstronomy.com

A vehicle horn is a sound-making device used to warn others of the approach of the vehicle or of its presence. Automobiles, trucks, ships, and trains are all required by law to have horns. Bicycles are also legally required to have an audible warning device in many jurisdictions, but not universally, and not always a horn.

Bicycle

Classic bicycle

Bicycle

A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....

horns usually consist of a single horn operating at a single resonance frequency

Resonance

In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...

, with a reed

Reed (instrument)

A reed is a thin strip of material which vibrates to produce a sound on a musical instrument. The reeds of most Woodwind instruments are made from Arundo donax or synthetic material; tuned reeds are made of metal or synthetics.-Single reeds:Single reeds are used on the mouthpieces of clarinets...

made of steel located in the throat of the horn, and supplied with air by a rubber squeeze bulb. Other variations include battery

Battery (electricity)

An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

operated horns, and small air horn

Air horn

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 trucks, fire trucks, and some ambulances for...

s powered by a small can of compressed gas.

Automobile

Oliver Lucas of Birmingham, England developed a standard electric car horn in 1910. Automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

horns are usually electric, driven by a flat circular steel diaphragm

Diaphragm (acoustics)

In the field of acoustics, a diaphragm is a transducer intended to faithfully inter-convert mechanical motion and sound. It is commonly constructed of a thin membrane or sheet of various materials. The varying air pressure of the sound waves imparts vibrations onto the diaphragm which can then be...

that has an electromagnet

Electromagnet

An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current. The magnetic field disappears when the current is turned off...

acting upon it and is attached to a contactor that repeatedly interrupts the current to the electromagnet. This arrangement works like a buzzer

Buzzer

A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical, or piezoelectric. Typical uses of buzzers and beepers include alarm devices, timers and confirmation of user input such as a mouse click or keystroke....

or electric bell

Electric bell

An electric bell is a mechanical bell that functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing or clanging sound...

and is commonly known as "sounding" or "honking" one's horn. There is usually a screw to adjust the distance/tension of the electrical contacts for best operation. A spiral exponential horn shape (sometimes called the "snail") is cast into the body of the horn, to better match the acoustical impedance of the diaphragm with open air, and thus more effectively transfer the sound energy. Sound levels are approximately 107-109 decibel

Decibel

The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...

s, and current draw 5-6 ampere

Ampere

The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...

s.

Horns can be used singly, but are often arranged in pairs to produce a chord consisting of two notes, sounded together; although this only increases the sound output by 3 decibel

Decibel

s, the use of two differing frequencies with their beat frequencies

Beat (acoustics)

In acoustics, a beat is an interference between two sounds of slightly different frequencies, perceived as periodic variations in volume whose rate is the difference between the two frequencies....

and missing fundamental

Missing fundamental

A sound is said to have a missing fundamental, suppressed fundamental, or phantom fundamental when its overtones suggest a fundamental frequency but the sound lacks a component at the fundamental frequency itself....

is more perceptible

Psychoacoustics

Psychoacoustics is the scientific study of sound perception. More specifically, it is the branch of science studying the psychological and physiological responses associated with sound...

than the use of two horns of identical frequency, particularly in an environment with a high ambient noise level

Ambient noise level

In atmospheric sounding and noise pollution, ambient noise level is the background sound pressure level at a given location, normally specified as a reference level to study a new intrusive sound source.Ambient sound levels are often measured in order to map sound conditions over a...

. Typical frequencies of a pair of horns of this design are 500 and 405–420 Hz (approximately B₄ and G#₄).

Some cars, and many motor scooters or motorcycle

Motorcycle

A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...

s, now use a cheaper and smaller alternative design, which, despite retaining the name "horn", abandons the actual horn ducting and instead relies on a larger flat diaphragm to reach the required sound level. Sound levels are approximately 109-112 decibels, and current draw 2.5-5 amperes. Again, these horns can be either single, or arranged in pairs; typical frequencies for a pair are 420-440 and 340–370 Hz (approximately G#₄-A₄ and F₄-F#₄) for this design.

A horn grille is a part of some designs of automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

or other motor vehicle that has an electric horn, such as a motor scooter.

The radiator

Radiator

Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, and electronics...

s of modern cars no longer determine the shape of the grilles, which have become more abstract, the radiator being of different proportions from the grille and over 15 centimetres behind it. Usually grilles are now designed such that the sound of a horn can readily come out through them. But those designs which maintain the notion that the shape of the grille shall reflect the shape of the radiator behind it no longer have front fenders with rather large crevices which would permit the old trumpet-shaped horns to be mounted on top of them. Thus some cars, often British ones, have a pair of round horn grilles mounted on either side of the radiator grille, behind each of which a horn is located. A luxury car's horn grilles are usually chrome-plated.

Cars with rear engines, such as the Volkswagen Beetle

Volkswagen Beetle

The Volkswagen Type 1, widely known as the Volkswagen Beetle or Volkswagen Bug, is an economy car produced by the German auto maker Volkswagen from 1938 until 2003...

and the early Porsche

Porsche

Porsche Automobil Holding SE, usually shortened to Porsche SE a Societas Europaea or European Public Company, is a German based holding company with investments in the automotive industry....

s, necessarily have no radiator grilles in front, and so have horn grilles placed below their headlights.

Some motor scooters have this feature as well, placed below the handlebars. Their horn grilles may be cheap plastic. These vehicles and the cheaper cars have only one horn.

Truck

A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...

(lorry) horns may be electromagnetic klaxons of design similar to those of automobiles. Often they are not electrically driven, but are purely acoustic, driven by air from an air compressor

Air compressor

An air compressor is a device that converts power into kinetic energy by compressing and pressurizing air, which, on command, can be released in quick bursts...

which diesel trucks already have on board to operate the air brakes

Air 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...

. Such air horn

Air horn

s are often used as trim items, with chromed

Chrome plating

Chrome plating, often referred to simply as chrome, is a technique of electroplating a thin layer of chromium onto a metal object. The chromed layer can be decorative, provide corrosion resistance, ease cleaning procedures, or increase surface hardness.-Process:A component to be chrome plated will...

straight horns mounted on top of the cab. This design may also be installed on customized automobiles, using a small electrical compressor. Usually two are used, sometimes more. The frequencies vary in order to produce a variety of different chords, but in general are lower than those of automobile horns; for instance 125 through 180 Hz (approximately B₂-F#₃). Sound levels are approximately 117-118 decibels.

Train

Train horn

Train horns are audible warning devices found on most diesel and electric locomotives. Their primary purpose is to alert persons and animals to the presence of a train, especially when approaching a grade crossing. They are also used for acknowledging signals given by railroad employees Train horns...

s can be grouped from one to five horns, to form a chord

Chord (music)

A chord in music is any harmonic set of two–three or more notes that is heard as if sounding simultaneously. These need not actually be played together: arpeggios and broken chords may for many practical and theoretical purposes be understood as chords...

that has the notes sounded together; these are operated by compressed air from the air system.

Ships

Ships signal to each other and to the shore with horns (sometimes referred to as whistles) that are driven with compressed air or from steam tapped from the power plant. Low frequencies are used because they travel further than high frequencies; ships horns have been heard as far as ten miles away. Traditionally, the lower the frequency, the larger the ship. The RMS Queen Mary

RMS Queen Mary

RMS Queen Mary is a retired ocean liner that sailed primarily in the North Atlantic Ocean from 1936 to 1967 for the Cunard Line...

, an ocean liner

Ocean liner

An ocean liner is a ship designed to transport people from one seaport to another along regular long-distance maritime routes according to a schedule. Liners may also carry cargo or mail, and may sometimes be used for other purposes .Cargo vessels running to a schedule are sometimes referred to as...

launched in 1934, had three horns based on 55 Hz, a frequency chosen because it was low enough that the very loud sound of it would not be painful to the passengers. Modern International Maritime Organization

International Maritime Organization

The International Maritime Organization , formerly known as the Inter-Governmental Maritime Consultative Organization , was established in Geneva in 1948, and came into force ten years later, meeting for the first time in 1959...

regulations specify ships' horn frequencies to be in the range 70–200 Hz for vessels that are over 200 meters in length.

Portable aerosol-driven air horn

Air horn

s are used for small craft water safety as well as for sports events and recreational activities.

Foghorns

Foghorn

A foghorn or fog signal or fog bell is a device that uses sound to warn vehicles of hazards or boats of the presence of other vehicles in foggy conditions. The term is most often used in relation to marine transport...

s use low frequency tones to warn ships away from unseen coastlines. The large horn mouth is aimed out to sea.

Stationary emergency

Many localities have rotating or stationary horns mounted on buildings or poles to warn residents of emergency conditions such as severe storms. They are also used as civil defense siren

Civil defense siren

A civil defense siren is a mechanical or electronic device for generating sound to...

s and emergency service sirens

Siren (noisemaker)

A siren is a loud noise making device. Most modern ones are civil defense or air raid sirens, tornado sirens, or the sirens on emergency service vehicles such as ambulances, police cars and fire trucks. There are two general types: pneumatic and electronic....

which often employ one or more acoustic horns to focus or distribute the sound.

Klaxon

Klaxon is a trademark for a brand of electromechanical horn or alerting device. Mainly used on automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

s, train

Train

A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...

s and ship

Ship

Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

s, klaxon horns produce an easily-identifiable sound often transcribed onomatopoeiacally as "awooga" or "ah-oo-gah". Like most mechanical horns, the klaxon has largely been replaced by solid-state electronic alarms, though the memorable tone itself has persisted.

The klaxon horn's characteristic sound is produced by a spring-steel diaphragm with a rivet in the center that is repeatedly struck by the teeth of a rotating cogwheel. The diaphragm is attached to a horn

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...

that acts as an acoustic transformer and controls the direction of the sound.
In the first klaxons, the wheel was driven either by hand or an electric motor. American inventor Miller Reese Hutchison

Miller Reese Hutchison

Miller Reese Hutchison was an American electrical engineer and inventor. He developed some of the first portable electric devices, such as a vehicle horn and a hearing aid.-Early life:...

(later chief engineer of Thomas Edison

Thomas Edison

Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...

) patented the mechanism in 1908.
The Lovell-McConnell Manufacturing Co. of Newark, New Jersey

Newark, New Jersey

Newark is the largest city in the American state of New Jersey, and the seat of Essex County. As of the 2010 United States Census, Newark had a population of 277,140, maintaining its status as the largest municipality in New Jersey. It is the 68th largest city in the U.S...

bought the rights to the device and it later became standard equipment on General Motors

General Motors

General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...

cars.
Franklyn Hallett Lovell Jr., the founder, coined the name klaxon from the Ancient Greek verb klazō, "to shriek".

Klaxons were first fitted to automobiles and bicycle

Bicycle

s in 1908. Electric klaxons were the first electrical devices to be fitted to private automobiles. They were originally powered by 6-volt dry cell

Dry Cell

-Dry Cell's formation:Part of the band formed in 1998 when guitarist Danny Hartwell and drummer Brandon Brown met at the Ratt Show on the Sunset Strip. They later met up with then-vocalist Judd Gruenbaum. The original name of the band was "Beyond Control"....

s, and from 1911 by rechargeable batteries

Rechargeable battery

A rechargeable battery or storage battery is a group of one or more electrochemical cells. They are known as secondary cells because their electrochemical reactions are electrically reversible. Rechargeable batteries come in many different shapes and sizes, ranging anything from a button cell to...

. Later hand-powered versions were used as military evacuation alarms and factory sirens. The klaxon is also remembered for its use as a submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

dive alarm in World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

.

The Klaxophone

Klaxophone

The Klaxophone is a musical instrument created by the American composer Henry Fillmore. Made of twelve car horns, it was created for use in his 'Klaxon March which was composed in 1929 for the Cincinnati, USA Automobile Show. This piece featured the instrument mounted onto a table and powered by a...

is an instrument that makes use of the klaxon's unique sound.

The English company Klaxon Signals Ltd. has been based in Oldham

Oldham

Oldham is a large town in Greater Manchester, England. It lies amid the Pennines on elevated ground between the rivers Irk and Medlock, south-southeast of Rochdale, and northeast of the city of Manchester...

, Greater Manchester

Greater Manchester

Greater Manchester is a metropolitan county in North West England, with a population of 2.6 million. It encompasses one of the largest metropolitan areas in the United Kingdom and comprises ten metropolitan boroughs: Bolton, Bury, Oldham, Rochdale, Stockport, Tameside, Trafford, Wigan, and the...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

for the last 80 years, with premises also in Birmingham

Birmingham

Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...

. The French Klaxon company was acquired by the Italian Fiamm Group in the 1990s. In 2005 Klaxon Signals sold the rights for the hooter or klaxon range to Moflash Signalling Ltd., based in the original Klaxon Factory in Birmingham England. The Famous Klaxet ES and A1 hooters returned home to Birmingham after 10 years.

External links

Authentic Navy Alarm Sounds
Pages from a klaxon horn adjustment manual with diagrams

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Bicycle

Automobile

Truck

Train

Ships

Foghorns

Stationary emergency

Klaxon

See also

External links