Unfortunately, even with a program like Adobe Audition, there is not much that you can do about this. It is the ambience from the arena.
Now, you might look into using a Compression VST and some EQ, to minimize it. I do not believe that PE has either of these by default, but it can use many VST plug-ins. I'd look here and see what they have. You will have to experiment to see which ones work with PE. If they do not, I *think* that Audacity will accept VST plug-ins. I know that PrPro and Audition both do.
Good luck, and plan on listening closely,
You don't think using the Dynamics effect would reduce this a bit?
You could certainly try it. I'd make sure that you have a good set of headphones, and plan on spending a lot of time trying everything you can. One good thing about most NLE's is that they are non-destructive. If you get beyond what Ctrl-z (Undo) can correct, you can always just replace the Audio from the Project Panel.
Without actually listening to, and experimenting with, a piece of Audio, it's mostly speculation, and previous experiences. Also, what sounds like a major improvement to me, might not fly with your hearing.
Good luck, and please report back with which Effects you found useful. We can all learn from others' experiences.