if its already "in the mix" you can consider inverse noise reduction. Bascially make a template of the noise you want removed and then apply the inverse to the sound. It is FAR easier to do this using something like Adobe audition's noise reduction facility than to do it yourself. Look into something like that.

IF it's not already "in the mix" then you can try a frequency keyed noise gate - or perhaps just a well tuned scientific filter - like a butterworth band stop or something. A frequency analysis of the offending section can give you a decent idea of where to aim.

IF it is in the mix and you just cant get rid of it?
There are also pschoacoustic approaches you could use: "Masking" for example, since the ear doesnt "hear" sounds that are preceeded or succeeded by certain louder noises then you could add a sound of this nature close to the other sound effectively hiding it.

Hope that helps.

[="http://www.hardwareanalysis.com/content/topic/220/"]link to stuff about noise cancellation[/]="http://www.hardware…"]link to stuff about noise cancellation[/] Sound Forge is the DAW used. in essence you need a discrete copy of the noise in isolation to really effectively use the inverse cancellation method. This is probably not the case for you. This link probably won't provide any solutions for the problem.

[[url=http://="http://www.scienced…"]ScienceDirect - Measurement : Image noise reduction using Wiener filtering with pseudo-inverse[/]="http://www.scienced…"]ScienceDirect - Measurement : Image noise reduction using Wiener filtering with pseudo-inverse[/] <-- This is an really esoteric paper on Image noise reduction using Wiener filtering with pseudo-inverse which would cover the concepts of noise cancellation (but in another domain) for the interested.
This link won't provide any solutions for the problem.

[="http://en.wikipedia.org/wiki/Psychoacoustics#Masking_effects"]Psychoacoustics - Wikipedia, the free encyclopedia[/]="http://en.wikipedia…"]Psychoacoustics - Wikipedia, the free encyclopedia[/] A nice little section on masking, could do with more content really. Again, you would have to experiment to get any type of decent results, it's just a description of the concept. This link won't provide any solutions for the problem.

[[url=http://="http://www.soundons…"]USING EQUALISATION[/]="http://www.soundons…"]USING EQUALISATION[/] using EQ - by someone who really knows what he is talking about. This could possibly provide a solution

There are also some post mastering tools like [[url=http://[/URL]="http://www.izotope…"]iZotope Alloy - Essential Mixing Tools[/]="http://www.izotope…"]iZotope Alloy - Essential Mixing Tools[/] and the Izotope itself that can programatically (ie sequenced) remove frequencies for an instant, if you were to play around just scooping out a section of frequency for a very short time perhaps you could "hide" the noise by simply reducing its relative power rather than removing it enitrely. I would probably do this in the absence of other options. this is possibly your best choice.

Be careful to affect other instruments as little as possible, less is more obviously. This is audio triage, not for the faint-hearted. Obviously not recording a bad sound is WAY better in the first place...

It is also possible to shift frequency ranges back and forward in time using these tools and this again MIGHT help you.
The noise may just "disappear" via accidental masking if you are REALLY lucky. have a play.

:) Happy reading. I genuinely think that lot would give you a very decent grounding in the concepts around the problem and maybe some possible solutions.

Hope that helps

Of course most of this presumes you can convert to the numeric domain. If you can't Drawmer noise gates, some careful Eqing and a few beers mght help :)