quadraphonic

[kwod-ruh-fon-ik]
adjective
  1. of, noting, or pertaining to the recording and reproduction of sound over four separate transmission or direct reproduction channels instead of the customary two of the stereo system: a quadraphonic recording.
Also four-channel, quadriphonic, quad·ra·son·ic [kwod-ruh-son-ik] /ˌkwɒd rəˈsɒn ɪk/.

Origin of quadraphonic

1965–70; quadra-, variant of quadri- + -phonic, as in stereophonic
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Word Origin and History for quadrasonic

quadraphonic

adj.

1969, irregular formation from quadri- "four" + phonic, from Greek phone "sound, voice" (see fame (n.)). The goal was to reproduce front-to-back sound distribution in addition to side-to-side stereo. The later term for the same idea, surround sound, is preferable to this.

Online Etymology Dictionary, © 2010 Douglas Harper