Hi there! I have a bunch of audio files each one with it's own default volume. I would like to normalize these sounds so they all have the same volume. How do i go about doing this? Is there any free or cheap software that does this?

i use adobe audition for that, but its not free. some free audio editors might have that. try searching for batch processing.

Grab Audacity, it's a free sample editor and can normalise amongst many other things.