Karlheinz Brandenburg

Karlheinz Brandenburg led the development of MP3, the audio compression format that made music portable over networks and destroyed the business model of the recording industry. Born in Erlangen, Germany in 1954, he studied electrical engineering and mathematics at the University of Erlangen-Nuremberg and took a doctorate there in 1989. His supervisor, Dieter Seitzer, had been refused a patent in 1977 for transmitting music over a telephone line, on the grounds that it was impossible. The bandwidth simply was not there, so Brandenburg's problem was how to throw away most of the data without the loss being audible. The answer was psychoacoustics. Human hearing has known limits: a loud tone masks quieter tones at nearby frequencies, and masks sounds immediately before and after it in time. Anything masked need not be transmitted at all. The encoder splits the signal into frequency bands, models what the ear will and will not perceive, and allocates bits accordingly, achieving compression of roughly twelve to one. He tested the codec on Suzanne Vega's Tom's Diner, an unaccompanied vocal that is unforgiving of artefacts, and by his account listened to it hundreds of times while refining the algorithm. The format was standardised by the Moving Picture Experts Group and the file extension .mp3 was chosen in 1995. The Fraunhofer Institute released an encoder as shareware, a cracked version spread, and the format was adopted far faster than its owners anticipated — through Winamp, Napster from 1999, and portable players culminating in the iPod. He directed the Fraunhofer Institute for Digital Media Technology and held a chair at Ilmenau. Licensing for MP3 ended in 2017.

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