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8/26/2016
Microphone Wikipedia, the free encyclopedia
Microphone From Wikipedia, the free encyclopedia
A microphone, colloquially nicknamed mic or mike (/ˈmaɪk/),[1] is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, twoway radios, megaphones, radio and television broadcasting, and in computers for recording voice, speech recognition, VoIP, and for nonacoustic purposes such as ultrasonic checking or knock sensors. Most microphones today use electromagnetic induction (dynamic microphones), capacitance change (condenser microphones) or piezoelectricity (piezoelectric microphones) to produce an electrical signal from air pressure variations. Microphones typically need to be connected to a preamplifier before the signal can be recorded or reproduced.
Contents 1 History 2 Components 3 Varieties 3.1 Condenser microphone 3.1.1 Electret condenser microphone 3.2 Dynamic microphone 3.3 Ribbon microphone 3.4 Carbon microphone 3.5 Piezoelectric microphone 3.6 Fiber optic microphone 3.7 Laser microphone 3.8 Liquid microphone 3.9 MEMS microphone 3.10 Speakers as microphones 4 Capsule design and directivity 5 Microphone polar patterns 5.1 Omnidirectional 5.2 Unidirectional 5.2.1 Cardioid, Hypercardioid, Supercardioid 5.3 Bidirectional 5.4 Shotgun and parabolic microphones 5.5 Boundary or "PZM" 6 Applicationspecific designs 7 Powering 8 Connectors 8.1 Impedancematching 8.2 Digital microphone interface 9 Measurements and specifications 10 Measurement microphones 10.1 Microphone calibration https://en.wikipedia.org/wiki/Microphone
An AKG C214 condenser microphone with shock mount
A Sennheiser dynamic microphone
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8/26/2016
Microphone Wikipedia, the free encyclopedia
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10.1 Microphone calibration Microphone array and array microphones Microphone windscreens See also References External links
History In order to speak to larger groups of people, there was a desire to increase the volume of the spoken word. The earliest known device to achieve this dates to 600 BC with the invention of masks with specially designed mouth openings that acoustically augmented the voice in amphitheatres.[2] In 1665, the English physicist Robert Hooke was the first to experiment with a medium other than air with the invention of the "lovers' telephone" made of stretched wire with a cup attached at each end.[3] German inventor Johann Philipp Reis designed an early sound transmitter that used a metallic strip attached to a vibrating membrane that would produce intermittent current. Better results were achieved with the "liquid transmitter" design in ScottishAmerican Alexander Graham Bell's telephone of 1876 – the diaphragm was attached to a conductive rod in an acid solution.[4] These systems, however, gave a very poor sound quality. The first microphone that enabled proper voice telephony was the (loosecontact) carbon microphone. This was independently developed by David Edward Hughes in England and Emile Berliner and Thomas Edison in the US. Although Edison was awarded the first patent (after a long legal dispute) in mid1877, Hughes had demonstrated his working device in front of many witnesses some years earlier, and most historians credit him with its invention.[5][6][7][8] The carbon microphone is the direct prototype of today's microphones and was critical in the development of telephony, broadcasting and the recording industries.[9] Thomas Edison refined the carbon microphone into his carbonbutton transmitter of 1886.[7][10] This microphone was employed at the first ever radio broadcast, a performance at the New York Metropolitan Opera House in 1910.[11][12]
Jack Brown interviews Humphrey Bogart and Lauren Bacall for broadcast to troops overseas during World War II.
David Edward Hughes invented a carbon microphone in the 1870s.
In 1916, C. Wente of Bell Labs developed the next breakthrough with the first condenser microphone.[13] In 1923, the first practical moving coil microphone was built. "The Marconi Skykes" or "magnetophon", developed by Captain H. J. Round, was the standard for BBC studios in London.[14] This was improved in 1930 by Alan Blumlein and Herbert Holman who released the HB1A and was the best standard of the day.[15]
Also in 1923, the ribbon microphone was introduced, another electromagnetic type, believed to have been developed by Harry F. Olson, who essentially reverseengineered a ribbon speaker.[16] Over the years these microphones were developed by several companies, most notably RCA that made large advancements in pattern control, to give the microphone directionality. With television and film technology booming there was demand for high fidelity microphones and greater directionality. ElectroVoice responded with their Academy Awardwinning shotgun microphone in 1963. https://en.wikipedia.org/wiki/Microphone
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