Normalizing or Dynamic compression ?
If you're after Dynamic compression ( AGC ) on WAV files try DeDynamic.exe from
http://www.divx-digest.com.
Matthias Lenk, the coder of this program, has done the main code in assembler so its quite fast. This code was the basis for his 'world famous' DeDynamic.ax DirectShowFilter that was implemented into PowerDivX3.1 and BSPlayer0.84, allowing us to reduce the Dynamics of the audio in our DivX movies on playback, being essential if no DRC was done on AC3 decoding.
Without that most movie soundtracks are total crap with unnatural high Dynamics, means in silent scenes ( dialogues ) you understand nothing and in loud scenes your PC speakers fall off the table. The filter works fine for compression levels of up to 15 dB, then you can hear a pumping effect that is quite typical for AGC ( this is why DRC should be applied on every AC3 on decoding, at least in level 'light' ). The code is done such that clipping is impossible and there is a possibility to have a 200% amplification as well.
The big benefit from this filter compared to others is the minimal usage of CPU power ( assembler ) , which is necessary for us DivXers as we want our CPU to decode the picture in good quality, maybe with some postprocessing on it, so we need every cycle

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The filter is called Dedynamic.ax and hosted from Doom9 (
http://www.doom9.net ) . If you contact me at cwiesner at t-online dot de i can organize a desription of the registry settings of the filter, f.e. if you plan to use it in oyur own programs/players as Blacksun has done in PowerDivX3.1 .