Back in the 1980s, boffins at the Fraunhofer Institute in Germany were looking for ways to make digital files smaller so they could be transferred down copper phone lines. After much experimentation, they came up with the with an compression algorithm called Motion Pictures Experts Group, Layer 3: MP3 for short.
The algorithm is based on the principles of psychoacoustics. Much of what a song contains is masked by other sounds, making them impossible for us to hear. Subtract those inaudible sounds from the song and you can reduce the size of its digital file by a factor of ten.
This brings me to Ryan McGuire, who is a Ph.D student at the University of Virginia Computer Music Centre. He figured out a way for us to hear the what the MP3 algorithm strips out. But what song to use in this demonstration? The same song that the Fraunhofer Institute used to create the MP3 in the first place: Suzanne Vega and “Tom’s Diner.”
The Fraunhofer guys played that song over and over and over again until they shrunk it down by 90% while maintaining its sonic integrity. So what did they strip out? That’s what McGuire managed to capture.
Cool, no? Read more on this sonic experiment at io9.