Why has the MP3 format become so popular in music?

One of the founding fathers of MP3 is rightly called the German engineer and mathematician Karlheinz Brandenburg. As a promising student at the University of Erlangen, in 1982 he was invited to participate in the development of technology that would allow music to be transmitted over telephone lines. Brandenburg and his colleagues were able to get closer to the real embodiment of the idea only in 1986, when more or less powerful computers appeared that made it possible to decompose signals into layers of sound for further transmission over wires.

However, Karlheinz’s group soon abandoned further research into sound transmission in this way due to the complexity of implementation. And she moved on to studying experiments with psychoacoustics - a science that deals with the psychological and physiological aspects of sound perception. These studies greatly contributed to the further progress of work on digital music compression.

MPEG specialists, when working on a breakthrough data compression standard, were divided into three groups, each of which was responsible for different levels of coding layers - Layer I, Layer II, Layer III. The coding principle itself took into account the fact that in an uncompressed state, CD audio transmits a large amount of information that is unnecessary for the ear. The compression principle being developed by MPEG used the method of masking individual sounds: a psychoacoustic model divided the entire frequency spectrum into parts with the same sound level and removed those that are not perceived by the human ear.

Layer III proved to be the most difficult layer to encode, as it broke the spectrum into the smallest parts, providing the most efficient audio compression. MPEG-1 Audio Layer 3 (MP3 for short) allowed music tracks to be compressed 11 times. If you try to compress the sound even more, its quality will deteriorate so much that it will become impossible to listen to the audio. To denote the quality of compressed files, the word bitrate began to be used - the term indicates how many units of information a particular file transmits per second. The highest quality in MP3 is for sounds with a bitrate of 320 kbit/s; the minimum acceptable for encoding musical sound has a bitrate of 128 kbit/s. When recording human speech, files can be compressed up to 96 kbps without loss of quality.