Surround sound

n. sound reproduction that uses three or more transmission channels and speakers to intensify the feeling of being surrounded by sound sources

Multichannel audio is the name for a variety of techniques for expanding and enriching the sound of audio playback by recording additional sound channels that can be reproduced on additional speakers. Surround sound refers to the application of multichannel audio to channels "surrounding" the audience (generally some combination of left surround, right surround, and back surround) as opposed to "screen channels" (center, [front] left, and [front] right).
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