For my free 1 month subscription at Audible, I chose NPR's All Things Considered, hoping to load the previous evening's show to listen to on the next morning's drive to work.

The sound quality is surprisingly bad. I tried both formats 3 and 4 and they make Daniel Schorr's somewhat mush mouthed speaking really hard to understand.

The beginning of third story from 11/12/2003 (Commentary: Turning Points in U.S. Policy) is particularly bad.

I tried the RealAudio & Windows Media streams from npr.org:

http://www.npr.org/rundowns/rundown.php?prgId=2&prgDate=12-Nov-2003

and the WM one showed the same kind of psychoacoustic-modelling-lossy-compression distortion as the Audible files, though to a lesser degree. The RM stream was much much better-- a little bright, but not tingly.

I know that mp3 is not great at low bitrates (Audible Format 4) and that some CODECs are better optimized for speech (using things like CELP). That's why I tried Format 3. Even though it's smaller than 4, if it was a better model, it could have sounded better. No luck.

I'll have to try a book next & see if that's any better.

Incidentally, I was listening to all four versions on my PC, not my iPod.