MP3 Surround files are essentially ordinary MP3s with an additional layer of information that tells compatible players where to place sounds. New devices designed to support the format deliver accurate surround sound, whether through a 5.1-channel system or simulated through a pair of stereoheadphones. The format adds minimal overhead, consuming just 15 additional bits per second. And it is backward-compatible, so MP3 Surround files will play on any device that supports your plain vanilla MP3, only sans surround. In order for you to hear MP3 Surround today, you'll need a computer with the playback software installed (available at all4mp3.com).