Dolby Digital is the trademark for Dolby Laboratories' AC-3 lossy audio compression (or data reduction) system. It is a system for coding and decoding digital audio sound so that it occupies less space on the recording medium.
Dolby Digital is by far the most popular format, with more cinemas equipped for Dolby Digital playback and more Dolby Digital titles in release.
Dolby Digital introduced 5.1-channel digital sound. The numbering refers to five full-range channels, plus a subwoofer channel (the .1) that covers the lowest one-tenth of the audible range. With digital sound each of the channels is completely discrete, so the audience hears exactly the same soundtrack as the director heard in the studio. The dynamic range (the ratio of the loudest sounds to the softest) is significantly improved over analog formats for more a more dramatic presentation. The full-range surround channels make lifelike special effects possible-think helicopters flying overhead. And the subwoofer sound can often be felt as well as heard.
Digital Film - DTS (Digital Theater System)
Digital Film - Film and Director
Dolby Digital http://en.wikipedia.org/wiki/Dolby_Digital [Accessed 27 Oct, 2004]
--Hao Zhang 21:01, 27 Oct 2004 (EST)
