Background noise removal software


I have some original audio on a MacOSX system, the voice has been a little swamped by the sound of a projector next to voice.

I am looking for some software to aid the recovery of the voice and remove only the background if possible.

I am looking for software that can sample the regions of a recording that contain only the background and can then use that to scrub the background from the voice.

Any other ideas would be very welcome.

Playing the tracks through itunes with the graphics equalizer preset to Vocal Booster *may* help clear up the voice. If that works you could then tinker with the frequencies to further isolate the background noise.
You could then use the audio out to record to another format. You could even use a vhs recorder. Then play back to the mac and re-encode to mp3 or whatever.
sounds crazy, but it might just work.
I use Audacity (free for Mac/WIn) for that and it works decently. And it's pretty easy to use the Noise Removal plugin.

Keep in mind that you can only filter out so much of the background noise before the voices you want to keep start sounding wierd.

I have used it to clean up poor quality meeting recordings with some good success.