What's the easiest way to normalise an audio recording?

I believe audacity can do it. It’s a nice full featured free audio editor that run on just about everything.

Another option if you’re just listening to music tracks in your collection is Replay Gain. This tags your music with the proper volume level adjustments to normalize everything. The good thing about replay gain is that it does not alter the audio itself. The bad thing is that it requires support in your audio player.

Definitely Mp3Gain. http://mp3gain.sourceforge.net/

It’s free, it’s fantastic, it’s reversible, it’s customizable, and it can do 10,000 songs at once.

The Conversations Network has something they call the Levelator, which you can get for free. Runs on Windows, OSX, and Linux.

Thanks all, great help.

@mdy: Exactly what I was looking for! Thanks!

Depending on the Program you are running it is fairly easy. If you right click audio patern/ wave patern (or drag the cursor across the selected area of choice) then once you have selected the audio in question you can either right click once again and choose editing the click on normalize. also you can choose from the editing tab on the top of the window and choose normalize. this is possible in wav pad, mix pad,(NCH products) Sony sound forge, sony acid, Power Audio, Audacity, Golden,And many more. Oh and the Nch Programs have this choice on a menu sidebar. all available on download.net