Dolby Digital

Dolby Digital - a digital surround sound system developed by Dolby laboratories. It offers from 1 to 5.1 channels of audio reproduction: front left, front right, front centre, surround left, surround right and a dedicated Low Frequency Effects (bass) channel, represented by the '.1.' DVD players with Dolby Digital capability can provide a backward-compatible mixdown of the five main channels to four for Dolby Pro-Logic playback.