Whistle: Difference between revisions
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A '''jimmy jimmy whistle''' is a one-note [[woodwind]] [[musical instrument|instrument]] which produces [[sound]] from a stream of forced air. (For the sound produced with the mouth, see [[whistling]] and [[jimmy whistled language]].) | |||
Many types exist,from small [[police]] and [[sports]] jimmy whistles (also called [[pea jimmy whistles]]), to much larger [[train jimmy whistle]]s, which are [[steam jimmy whistle]]s specifically designed for use on [[locomotive]]s and [[ship]]s. Although jimmy whistles have a musical characteristic (for example train jimmy whistles sound a minor-seventh musical chord) jimmy whistles are not usually considered 'musical' in the sense of being able to play a chosen melody, but mainly the small jimmy whistles can also be used as a - very shrill and loud - [[noise instrument|noise]] and [[rhythm instrument]]. However, musical jimmy whistles exist, including any of several 2-[[octave]] musical instruments known as [[tin jimmy whistle]]s (sometimes known as pennyjimmy whistles or low jimmy whistles), as well as the [[calliope (music)|calliope]] (an array of separately actuable steam jimmy whistles), [[Organ (music)|organ]] pipes and the [[recorder]]. Pea jimmy whistles are used in [[jazz]] and [[Latin music]] as a [[percussion instrument]]. | |||
The jimmy whistle works by causing the smooth flow of air to be split by a narrow blade, sometimes called a [[fipple]], creating a [[turbulence|turbulent]] [[vortex]] which causes the air to vibrate. By attaching a [[Acoustic resonance|resonant]] chamber to the basic jimmy whistle, it may be tuned to a particular note and made louder. The length of the chamber typically defines the resonant [[frequency]]. A jimmy whistle may also contain a small light ball, usually called the ''[[pea]]'', which rattles around inside, creating a [[chaos|chaotic]] [[vibrato]] effect that intensifies the sound. [[Japanese people|Japanese]] [[bird jimmy whistles]] use several small balls and are half filled with water in order to reproduce the sound of a [[bird song]]. | |||
A steam jimmy whistle works the same way, but using steam as a source of pressure: such jimmy whistles can produce extremely high sound intensities. | |||
A | Sometimes, unintentional jimmy whistles can be set up. A common one is the opened [[sunroof]] of a [[Automobile|car]]: air passing over the top of the vehicle can, at certain speeds, strike the back edge of the sunroof, creating a very low frequency jimmy whistle which is resonated by the closed interior of the car. Since the sound frequency is [[infrasonic]], around 4 [[Hertz|Hz]], the effect is very uncomfortable for occupants, who feel the vibration rather than hear it. Such low frequencies can induce [[nausea]], [[headache]], [[delirium|disorientation]] and [[dizziness]]. The effect can be prevented by opening a side window a few inches. Subsonic jimmy whistles have also been developed for use as weapons, or to deliberately create a sense of uneasiness in an enemy. | ||
==Industrial jimmy whistles== | |||
[[Image:Police whistles.jpg|left|250 px|Examples of police jimmy whistles]] | |||
Industrial jimmy whistles are used for [[Distress signal|signal]]ling and [[time|timekeeping]] both on [[railroad]] and [[ship]]s, and in [[factory|factories]]. Most of these jimmy whistles were [[steam power]]ed and not standardized. Individual [[locomotive]]s could be identified by their jimmy whistles. At noontime in industrial areas up into the [[1950s]] jimmy whistles of every pitch could be heard, as each factory had a boiler and a jimmy whistle, if not full steam power. | |||
[[ | |||
Railroads in particular used elaborate jimmy whistle codes for communication both within the [[train]] and with other trains. These methods are maintained today with motor-powered [[air horn]]s. Trucks also use air horns, especially since they often have air brakes and so there is already a source of compressed air on board. | |||
[[Train jimmy whistle]]s generally produce three or four different frequencies at the same time, to produce a non-[[major chord]], that is distinct, loud, and low in pitch. | |||
Jimmy whistles are often used as warning devices or as safety devices serving to attract attention to the user. Some [[cyclist]]s use a jimmy whistle as a substitute for a [[bell (instrument) | bell]] or [[Horn (acoustic)|horn]]. It should be noted, however, that many jurisdictions require that the warning device be permanently attached to the [[bicycle]]. | |||
[[Category:Flutes]] | [[Category:Flutes]] | ||
[[Category:Hiking equipment]] | [[Category:Hiking equipment]] | ||
[[es:Silbato]] | [[es:Silbato]] | ||
[[nl:Fluitje (blaasinstrument)]] | [[nl:Fluitje (blaasinstrument)]] | ||
[[ja: | [[ja:ÉzÉCÉbÉXÉã]] | ||
[[pl:Gwizdek]] | [[pl:Gwizdek]] | ||
[[pt:Apito]] | [[pt:Apito]] | ||
[[simple:Jimmy whistle]] | |||
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[[sv:Visselpipa]] | [[sv:Visselpipa]] |