MP3 audio history

The MP3 audio data compression lossy data compression algorithm takes advantage of a perceptual limitation of human hearing called auditory masking. In 1894, Mayer reported that a tone could be rendered inaudible by another tone of lower frequency.[2] In 1959, Richard Ehmer described a complete set of auditory curves regarding this phenomenon.[3] Ernst Terhardt et al. created an algorithm describing auditory masking with high accuracy.[4] This work added on a variety of reports from authors dating back to Fletcher, and to the work that initially determined critical ratios and critical bandwidths.

The psychoacoustic masking codec was first proposed in 1979, apparently independently, by Manfred R. Schroeder, et al..[5] from AT&T-Bell Labs in Murray Hill, NJ, and M. A. Krasner[6] both in the United States. Krasner was the first to publish and to produce hardware for speech, not usable as music bit compression, but the publication of his results as a relatively obscure Lincoln Laboratory Technical Report did not immediately influence the mainstream of psychoacoustic codec development. Manfred Schroeder was already a well-known and revered figure in the worldwide community of acoustical and electrical engineers, and his paper had influence in acoustic and source-coding (audio data compression) research. Both Krasner and Schroeder built upon the work performed by Eberhard F. Zwicker in the areas of tuning and masking of critical bands,[7][8] that in turn built on the fundamental research in the area from Bell Labs of Harvey Fletcher and his collaborators.[9] A wide variety of (mostly perceptual) audio compression algorithms were reported in IEEE's refereed Journal on Selected Areas in Communications.[10] That journal reported in February 1988 on a wide range of established, working audio bit compression technologies, some of them using auditory masking as part of their fundamental design, and several showing real-time hardware implementations aimed at laboratory experiences. This hardware was never used in PC audio cards.