Noun

stereo (plural stereos)

1. A system of recording or reproducing sound that uses two channels, each playing a portion of the original sound in such a way as to create the illusion of locating the sound at a particular position, each offset from the other, thereby more accurately imitating the location of the original sound when the recorded or reproduced sound is heard.
2. A device used for playing music, usually in the home, that reproduces sound using stereo.

   He liked to listen to classical music on his stereo.

Synonyms

• (device): hi-fi, music centre

Adjective

stereo (not comparable)

1. Of sound, music, etc, recorded in stereo.
2. Of a pair of images: one depicting the view as would be seen from one eye and the other from the other eye, so that when viewed appropriately, they combine to give an impression of three dimensions.

Synonyms

• (of sound): in stereo, stereophonic
• (of a pair of images): in stereo, stereographic

Antonyms

• (sound): mono, monophonic

Stereophonic sound, commonly called stereo, is the reproduction of sound using two or more independent audio channels through a symmetrical configuration of loudspeakers in such a way as to create the impression of sound heard from various directions, as in natural hearing. It is often contrasted with monophonic, or "mono" sound, where audio is in the form of one channel, often centered in the sound field (analogous to a visual field).

Stereo recordings are used in FM broadcasting and Digital Audio Broadcasting (DAB) and in several television systems. To record in stereo, sound engineers use various methods, including using two directional microphones, two parallel omnidirectional microphones, or more complex techniques. Several monophonic records, such as the original Broadway cast recordings of Oklahoma! (1943), Carousel (1945), and South Pacific (1949), were once reissued in "fake" stereo to create the impression that the sound was originally recorded in that medium.

The first stereo transmission was made telephonically by Clément Ader in 1881. The BBC made radio's first stereo broadcast in December 1925. In the 1930s, Alan Blumlein of EMI patented stereo records, stereo films, and also surround sound. Harvey Fletcher of Bell Laboratories investigated techniques for stereophonic recording and reproduction. The first commercial motion picture to be exhibited with stereophonic sound was Walt Disney's Fantasia (1940). By the mid-1950s, multichannel sound was common for big-budget Hollywood motion pictures. In 1953, Remington Records began taping some of its sessions in stereo, with the first stereophonic phonograph discs available to the general public in 1958. The U.S. Federal Communications Commission announced stereophonic FM broadcasting technical standards in April 1961, and licensed regular stereophonic FM radio broadcasting, to commence that same year. In 1984, multichannel television sound was adopted by the FCC as the United States standard for stereo television transmission.