Why is data compression necessary for digital multichannel audio formats?
In order for the digital encoding and sound processing of the 5.1 channels to be possible, data compression is a necessity. Dolby Digital 5.1 uses a special compression algorithm that is based on perceptual audio coding and the masking phenomenon. When neighboring frequencies are reproduced at high levels, the human perception of sound masks certain frequencies, which would otherwise be audible. This masking phenomenon is used for the reduction of data volume. Therefore all audio information that is not perceived is removed.
