A compression technique that uses perceptual encoding for storage and delivery. MPEG-2 audio format includes individual multichannel audio content.

MPEG stands for the "Moving Picture Experts Group", working under the joint direction of the International Standards Organization (ISO) and the International Electro-Technical Commission (IEC). This group workson standards for the coding of moving pictures and associated audio. MPEG audio files can be either layer I, II or III. Increasing layer numbers add complexity to the format and require more effort to encode and decode. However, they also provide higher playback quality for the sample bit rate. Files can have sampling rates of 32000, 44100 and 48000 Hz and be in stereo or mono. MPEG compression is a lossy algorithm based on perceptual encodings, which can achieve high rates of compression without noticable decreases in quality. Typical compression rates are around 10-to-1.

MPEG defined three levels or layers of audio compression. Which layer a type of equipment uses depends on the desired level of compression. These three layers compress audio data streams by roughly four, six and eight times respectively, around 64, 128 and 192Kbit/s per channel. In practical terms, these compression rates make possible radio broadcasting of CD-quality music. All three layers are defined for both monaural and stereo sound. Definitions for surround sound and other high fidelity applications are under consideration.