Dolby Digital is the most prominent example of digital data transmission for audio application. Dolby Digital is the de facto standard for DVDs worldwide, the mandated standard for DTV (Digital Television) in the U.S., and has gathered a lot of support in the computer gaming industry.

This format is similar to Dolby Digital 5.1, except it includes a sixth sound channel for a speaker positioned right behind the listener. This speaker serves the same function as the front central speaker -- it anchors the left and right speakers. The sixth channel works a little differently than the other five: The EX receiver extracts a signal from the rear left and right channels. At this time, Dolby Digital EX is not used widely, but in the future more DVDs and digital broadcasts will likely take advantage of its expanded surround-sound capabilities.