Is there a relatively easy way to remove background noise such as gunfire? I've captures a few gunshot sounds from war movies but I need to eliminate the background noises so they sound good. One of the sounds I recorded is http://wraiyth.freesuperhost.com/Garand.wav which is two garand shots plus the ping when the clip is ejected. What would be the best way to go about enhancing this and others like it?

Some kind of band filter perhaps?

http://audacity.sourceforge.net/ - Audacity has excellent built in noise reduction stuff, have a play if you've not already. It is also legitmately free.

I can't get the noise reduction in Audacity to work well

Quote: Original post by Wraiyth
Is there a relatively easy way to remove background noise such as gunfire? I've captures a few gunshot sounds from war movies but I need to eliminate the background noises so they sound good.
One of the sounds I recorded is http://wraiyth.freesuperhost.com/Garand.wav which is two garand shots plus the ping when the clip is ejected. What would be the best way to go about enhancing this and others like it?

Some background noises are easier to supress than others. Capturing from movies probably isn't a very good way to do it, especially if you want a clean sound. You can use the previous posters suggest of using some form of band pass filtering provided there isn't alot of over lap in the sound frequencies in the background and the sounds you want to keep. If you're sound editor has some like an equalizer you can atenuate the different frequencies until it sounds good. What tools are using to enhance these sounds, maybe we can give more specific suggestion if we know what you're using.

Quote: Original post by paulecoyote
http://audacity.sourceforge.net/ - Audacity has excellent built in noise reduction stuff, have a play if you've not already. It is also legitmately free.

Do you have a copy of Nero Burning Rom? Their Wave Editor tool has a decide noise anaylsis and reduction tool.

As iMac says then, you may have to filter out specific bands. Noise reduction is tricky when the noise you want to keep is sometimes at the same pitch & frequency as the noise you want to get rid of.

SoundForge has tons of plugins, as does Cubase... but both are expensive professional tools that are not necessarily user friendly.

May be you might get lucky and a very bored musician might do it for you.

Careful with the whole copyright thing with using war movies - though incredibly unlikely to trace what and where I guess. You may be better off searching the web for clean samples from gunclubs or something, I'm sure there's got to be someone out there with a gun and microphone [wink]

May be try thinking "out the box" too (feel dirty for saying that)... but, well, try some Drum and Bass heads, or other music that people may use gunshots in while composing. If you ask nicely someone may give you a sample.

This forum here for example: http://www.dogsonacid.com/

The problem with noise reducion is defining what 'noise' is, for any given sound. Once you have that, the issue is almost solved. (Or at least, known to be unsolvable.)

Can you remove background noise based on how loud it is? For example if you've got gunfire in the background and you've got one in the foreground its going to be much louder, so can you exlude the background noise by its sound level?

Not really. Sound is additive and the only reason the human ear is able to detect that there are 2 sounds at once, is because of the subtle differences between the two sounds. If you removed those differences and overlaid one gunshot with an identical gunshot at a quieter volume, all you would hear is one gunshot slightly louder than the first. The computer has the same problem for any two sounds, given that it has no innate or learned knowledge of the subtleties that make one sound different from another. A loud sound plus a quiet sound equals a very loud sound - all other information is essentially lost in the act of combination. If the two sounds don't differ in any significant way except for amplitude, then you can't really do anything about this.