MP3 (MPEG-1, LAYER 3)

Using MPEG audio, one may achieve a typical data reduction of 1:4 by Layer 1 (corresponds with 384 Kbps for a stereo signal), 1:6...1:8 by Layer 2 (corresponds with 256..192 Kbps for a stereo signal), 1:10...1:12 by Layer 3 (corresponds with 128..112 Kbps for a stereo signal).