How to Normalize Audio in Multiple Video Files

I'm new to this forum, so hello and thanks to everyone who helps, or tries to help in advance.
I'm looking for a program, preferably free, but I'll buy something if need be; that can normalize audio in multiple video files. Ideally, I'd like to be able to batch normalize, but if I need to do it one by one, that is fine. The majority of the videos are mov, mp4, mkv and avi files. I just need all of the videos to be at the same volume. Since they are from different sources, they are currently all over the place. I am using Windows Vista Ultimate, on a pretty good rig.I think that is all of the important information, but if there's anything I'm missing, feel free to let me know what else would be helpful. Again, thanks in advance...this would be a great help to me.

Tony

 

For AVI, this might help.

http://forum.videohelp.com/threads/255147-Mini-Guide-Normalizing-Audio-for-Multiple-AVI-files

 

Thanks, I checked out that post before, but only a handful of my videos are avi files.

 

Give Avidemux a try.