Any way to do noise reduction on streaming audio?

[DT4K]

I'm taking a class online. When I watch the lectures, the audio quality is pretty crappy.
Is there any free or very cheap utility or windows media player plug-in that will do noise reduction or allow me to try to clean up the sound in any way?
I watch and listen to the lectures through the school's web based client that uses Windows Media Player, so I can't just download the avi or mpeg or whatever file it is.

EDIT: If there is a way to capture the streaming audio and clean it up, that would work as well. But the ideal would just be to be able to apply some noise reduction techniques on the fly if something like that is possible.