Today, there are more mp3s in circulation than all other recording formats combined. This alone would be cause to write a book about them, but I became fascinated with mp3s because of how they are made. An mp3 encoder uses a mathematical model of the gaps and absences in human hearing to remove some of the data in an audio file, in order to make it smaller. If the encoder “thinks” you won’t hear part of a sound recording, it yanks it out on the encoding end, so that the resulting mp3 file is smaller, and therefore easier to transmit over data lines or to stockpile on hard drives and flash memories.
I wanted to know where this model of human hearing came from and what it could tell us about our contemporary sonic culture. The result is my new book, MP3:The Meaning of a Format.
The technology behind the mp3 is called “perceptual coding,” and I quickly discovered it has deep connections to the development of hearing science and telecommunications over the last hundred years. Everything we think we know about hearing in the state of nature is a result of the interactions between ears and media in the 20th century.
MP3s also point to the importance of compression in the development of communication technologies. Each generation of new media is usually sold to consumers as being of higher definition and greater verisimilitude than its predecessor (think of how DVDs and Blu-Ray have been marketed, for instance). But developments in compression and lower-definition transmission are equally important for everything from telegraphs, to telephones, to color television, to satellite transmission to the internet. This other history is less apparent because it is manifest inside our hard drives, and inside the massive infrastructures that allow us to move data around. It is not as shiny or sexy as the latest consumer gadget, but it could well be more important for everything from aesthetics to policy.