The Moving Pictures Experts Group
MP3, or MPEG-1 or MPEG-2 Audio Layer III to the mega-boffins, is a patented encoded format for digital audio. MPEG stands for Moving Pictures Experts Group, an international collaboration of engineers founded in 1988. One of the things these coders were first interested in was a phenomenon called auditory masking, which is all about using one sound to render another inaudible. The MPEG researchers wanted to use this to help develop efficient compression tools, or codecs, to apply to full-motion video and high-quality audio in digital form.
First they built a huge, refrigerator-sized machine, nicknamed ‘the helicopter’, that could squeeze a sound file down to just 8% of its original size, but that wasn’t especially convenient; they needed an algorithm that could replicate the same effect—and that’s where Karlheinz Brandenburg comes in.
MP3 is served at Tom’s diner
Brandenburg, part of the MPEG team, had been a PhD student at the German University of Erlangen-Nuremberg in the 1980s, when one of his professors instructed him to work on the conundrum of how one might transmit music over a digital ISDN phone line. The trick was to compress it without spoiling the auditory experience, and Brandenburg’s test-case wasn’t Beethoven or Wagner, but folk-singer Suzanne Vega’s pop song Tom’s Diner—a song he’d heard by chance from down the corridor.
The nuances of Vega’s voice on the a cappella track meant that Brandenburg’s new algorithm had to be really, really good at picking out which parts of the sound could be discarded without ruining the listener’s experience. Of course, after listening to the song several thousand times, he cracked it. So Brandenburg’s work, first at Erlangen, and then as a post-doctoral researcher at AT&T-Bell Labs, became the basis of what we’d recognise as modern audio compression systems.
Incredible shrinking music
So what does that mean for us, and for the music industry? Well, the genius of the MP3 is that its algorithm lets you massively shrink the amount of data needed to represent the original audio recording, while still making it sound authentic to most listeners. That means that while it almost always sounds just as good as the older recording formats we’d gotten used to, it’s also easier to store and to transfer—hence, today, you can carry a whole music library around on your portable player or your smartphone.
74 hours of tunes
The Nokia Lumia 920, for instance, has the capacity to fit up to 74 hours of music on there; a CD could only ever manage 74 minutes. So long, CDs! Online music file-sharing and quick downloading has become ubiquitous, and streaming services like Nokia Music are starting to replace radios. And it’s all thanks to Karlheinz Brandenburg, though he’s reluctant to take all the credit, insisting that ‘I know on whose shoulders I stand and who else contributed a lot.’
A genius and modest to boost? Our hero!