Since the fall of 1993, I have been interested in MPEG audio, a set of algorithms for reducing the space needed to store audio information. I have done a substantial amount of analytic listening to the compression system, and have recently ran an experiment for the California Institute of Technology's Projects in Music and Science class to gauge the "Perceived Accuracy" of the MPEG system.
Here is the final report I submitted on my experiment. For best results, it should be viewed with an HTML 2.0 (or later) capable browser, such as Netscape.
For more information about the MPEG effort, and pointers to hardware and software implementations of the MPEG audio system, you may wish to consult the MPEG Frequently Asked Questions file.