(
Inter-
IC 
Sound)  An internal digital audio interface for consumer electronics devices such as CD and DVD players, sound processors and digital TV (DTV).  I2S is also used between a digital controller and an analog/digital codec similar to the AC Link and HD Audio Link in AC'97 and HD Audio.  I2S employs a serial bus with three lines: one for multiplexed stereo audio and two for signaling.  See 
AC'97 and 
HD Audio.