However, the compression algorithms are up to theindividual manufacturers, and that is where proprietary advantage is obtained within the scope of a publicly available international standard. MPEG meets roughly four times a year for roughly a week each time. In between meetings, a great deal of work is done by the members, so it doesn't all happen at the meetings. The work is organized and planned at the meetings. Well, first you need to know how sound is stored in a computer.
Sound is pressure differences in air.
When picked up by a microphone and fed through an amplifier this becomes voltage levels. The voltage is sampled by the computer a number of times per second. For CD-audio quality you need to sample 44100 times per second and each sample has a resolution of 16 bits. In stereo this gives you 1.4 Mbit per second and you can probably see the need for compression. To compress audio MPEG tries to remove the irrelevant parts of the signal and the redundant parts of the signal.