Close window but not quit
On the Mac, most apps have the ability to close all the windows but not fully quit. However this is not the case for adobe audition. Audition takes a really long time to open, so it would be good to have no windows open but still be ready in the background should a new file be opened in audition. That way it is quick to open audition.
C Ross commented
Yes please! The problem with minimizing/hiding/etc is that the default behavior for many people is to close a file when preparing to open another, etc. Across all other Adobe products this is how it works. When you close your Audition doc and get ready to open another, you're immediately sitting there waiting for the app to load again. this should be a no-brainer and go to the top of the list, imo. : )
Mike Buckhout-White commented
Have you considered Minimizing the window into the dock (CMD-M)? You can also just Hide the app (CMD-H). Both ways will make the window go away and leave the program running in the background.