|1.||Compare commentary the recorded sound accompaniment to a film|
|2.||a narrow strip along the side of a spool of film, which carries the sound accompaniment|
|3.||(tr) to provide a continuous accompaniment of sounds, esp music|
in motion-picture technology, narrow band, usually along the margin of the film, that carries the photographic or magnetic sound record. In optical recording systems, sound waves modulate a beam of light; the sound track, which may be of variable density or of variable width, is a photographic record of the varying light. For sound reproduction, a beam of light is passed through the sound track onto a photocell connected, through an amplifier, to a loudspeaker. This optical system is the basic plan of sound reproduction in sound motion pictures. In stereophonic sound recording, a number of such bands may be used on the same film
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