Excessive need for sleep or a reduced need for sleep could be a side effect depending on the frequency. Running entrainment in the background all day isn't natural so like a dripping tap it can become annoying. For effectiveness listening for an hour and then giving it a break is probably best.
Use Varible Bitrate Compression if you want to keep the MP3 accurately close to the original source.
Alex
[This message has been edited by Alex K. Viefhaus (edited April 12, 2005).]
