From Fedora Project Wiki
Intro
The initial idea behind this article was two-fold: First, there needs to be an article explaining the way sound works in the OS. Second, there needs a merging and more logical layout for the troubleshooting sections found elsewhere.
I hope this helps and is accepted as the best way to go on this subject.
I would also like to see a graphical pyramid of the hierarchy of the various components and applications from input to output, or from source to speakers. Such would fit well into the second secton.