A specification from Dolby Digital and the Advanced Television Systems Committee (ATSC) for audio compression.The audio sampling rate is 48 kHz, and the system supports six channels in the Dolby Digital surround format. That format specifies multiple channel outputs, including center, left and right center, left and right surround, and low-frequency enhancement (LFE), also known as subwoofer. AC-3 is specified by the ATSC for use in high definition television (HDTV) and standard definition television (SDTV). See also ATSC, audio, channel, compression, HDTV, and SDTV.
(Active Coding-3) Dolby's third digital audio coding technology based on a perceptual coding method. Introduced in 1991 initially for surround sound in theaters, AC-3 is more advanced than AC-2 and provides six channels of audio in less space than a two-channel stereo CD. AC-3 and "Dolby Digital" are synonymous. See Dolby Digital, AC-1 and AC-2.