microphone

microphone
/muy"kreuh fohn'/, n.
an instrument capable of transforming sound waves into changes in electric currents or voltage, used in recording or transmitting sound.
[1875-80; MICRO-, in sense "enlarging" (extracted from MICROSCOPE) + -PHONE]

* * *

Device for converting sound waves into electric power that has wave characteristics essentially similar to those of the sound.

By proper design, a microphone may be given directional characteristics so that it will pick up sound primarily from a single direction, from two directions, or more or less uniformly from all directions. In addition to their use in telephone transmitters, microphones are most widely applied in hearing aids, sound-recording systems (principally magnetic and digital tape recorders), dictating machines, and public-address systems.

* * *

▪ electroacoustic device
      device for converting acoustic power into electric power that has essentially similar wave characteristics. While those on telephone transmitters comprise the largest class of microphones, the term in modern usage is applied mostly to other varieties.

      Apart from telephone transmitters, microphones are most widely applied in hearing aids, sound-recording systems (principally magnetic and digital tape recorders), dictating machines, and public-address systems. Microphones are extensively used in communications systems, radio or wire, to provide better response quality than with conventional telephone transmitters, or for hands-free operation.

 In a microphone, sound waves (sound-pressure variations in the air) are converted into corresponding variations in electric current in two operations that take place almost simultaneously. In the first, the sound wave impinges on a slightly flexible surface (diaphragm), causing it to move to and fro in a manner corresponding to the movement of the air particles. In the second, the diaphragm by its motion causes a corresponding change in some property of an electric circuit. Depending on the type of microphone, displacement of the diaphragm may cause variations in the resistance of a carbon contact (carbon microphone), in electrostatic capacitance (condenser microphone), in the motion of a coil (dynamic microphone) or conductor (ribbon microphone) in a magnetic field, or in the twisting or bending of a piezoelectric crystal (crystal microphone; see Figure—>). In each case, motion of the diaphragm produces a variation in the electric output. By proper design, a microphone may be given directional characteristics so that it will pick up sound primarily from a single direction (unidirectional), from two directions (bidirectional), or more or less uniformly from all directions (omnidirectional).
 

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • microphone — [ mikrɔfɔn ] n. m. • 1721; de micro et phone 1 ♦ Hist. des sc. Instrument augmentant l intensité des sons, de manière à les rendre perceptibles. 2 ♦ (1878; angl. microphone [1877]) Cour. Capteur électroacoustique transformant une vibration sonore …   Encyclopédie Universelle

  • microphone — mi cro*phone (m[imac] kr[ o]*f[=o]n), n. [Micro + Gr. fwnh sound, voice: cf. F. microphone.] (Physics) An instrument for converting sounds into electrical signals, for the purpose of recording or amplifying the sounds. It produces its effects in… …   The Collaborative International Dictionary of English

  • microphone — ou microphonium 1. (mi kro fo n ou mi kro fo ni om ) s. m. Instrument qui rend perceptibles les sons les plus faibles, quand il est en contact avec le corps sonnant. ÉTYMOLOGIE    Micro..., et terme grec signifiant voix. microphone 2. (mi kro fo… …   Dictionnaire de la Langue Française d'Émile Littré

  • microphone — UK US /ˈmaɪkrəfəʊn/ noun [C] ► a piece of equipment that you use to make your voice louder, or to record something: »Most laptops now come with a built in webcam and microphone for online chatting …   Financial and business terms

  • microphone — (n.) 1680s, ear trumpet for the hard of hearing, coined from Gk. mikros small (see MICA (Cf. mica)) + phone sound (see FAME (Cf. fame) (n.)). Modern meaning dates from 1929, from use in radio broadcasting and movie recording. Earlier, amplifying… …   Etymology dictionary

  • microphone — ► NOUN ▪ an instrument for converting sound waves into electrical energy which may then be amplified, transmitted, or recorded …   English terms dictionary

  • microphone — [mī′krə fōn΄] n. [ MICRO + PHONE] an instrument containing a transducer that converts the mechanical energy of sound waves into an electric signal, used in telephony, radio, sound amplification, etc. microphonic [mī΄krə fän′ik] adj …   English World dictionary

  • Microphone — For the indie film, see Microphone (film). Microphones redirects here. For the indie band, see The Microphones. A …   Wikipedia

  • Microphone — Pour les articles homonymes, voir Micro. Un microphone (ou plus simplement micro par apocope) est un dispositif de conversion des ondes sonores acoustiques d un milieu compressible en impulsions électriques. C est donc un capteur analogique. Le… …   Wikipédia en Français

  • microphone — noun ADJECTIVE ▪ boom, cordless, headset, radio, underwater, wireless ▪ condenser ▪ external …   Collocations dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”