Automatic noise reduction

Why not just get the Noise Profile (once) manually before running the Macro? While Audacity is open, it will retain that noise profile.

Why not just get the Noise Profile (once) manually before running the Macro? While Audacity is open, it will retain that noise profile.

I was going to ask about that. Audacity Noise Reduction will dump the profile if you restart the program, right? Is there any indication it’s doing that? What does it use for a profile if there isn’t one?


Harking back to the title of the thread, isn’t it possible to not have a manual profile by averaging all the sound in the show? Anything in the show for a very long time is probably noise. I think I have a very old program which uses that technique. No, it’s not perfect, but it’s better than nothing—and it’s completely automatic.


If you run Noise Reduction in a Macro, and there isn’t a noise profile, Noise Reduction will run “Step 1” (Get Noise Profile). If there is a noise profile, then it will run “Step 2” (Reduce the Noise).

So yes, you could run something like:

Import2:Filename="<path to file>noise.wav"
NoiseReduction:Use_Preset="<Factory Defaults>"
NoiseReduction:Use_Preset="<Factory Defaults>"

but much simpler and more efficient to just get the noise profile manually before running the macro.

I believe that to be the case.

IIRC there has been some discussion in the past about storing a noise profile (t be retained on exit from Audacity) but nothing eve progressed along those lines.

Would you want to lobby for such an enhancement ?

Only that when you run NR it will then go to phase-1 and request a noise profile.

What it does is request one.


You can use the sound finder and delete all the sound. You can tweak the sensitivity to get it right.

I posted about that earlier on with specififcs.

And if anyone is interested, here is the soundtrack I was able to edit together with the best audio quality I could muster with Audacity, which is pretty good for its 1950’s ish recording date:

I find your clarification very interesting. I’ve made a macro to run noise reduction after some removal of electric noise and low-frequency junk, therefore getting noise profile before running the macro is not an option. If I run my macro just after starting Audacity, it would work, but if I close the file (ctrl-w) and open another one, the older Noise Reduction profile is kept and I get an error. Is there a way to clean the noise profile at the beginning of the macro to make this macro more robust?

See my code here:

NotchFilter:frequency="60" q="1"
NotchFilter:frequency="120" q="1"
High-passFilter:frequency="40" rolloff="dB48"
SelectTime:End="6" RelativeTo="ProjectStart" Start="0"
NoiseReduction:Use_Preset="<Factory Defaults>"
NoiseReduction:Use_Preset="<Factory Defaults>"
Normalize:ApplyGain="1" PeakLevel="-3" RemoveDcOffset="1" StereoIndependent="0"
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f45="118.88467" f46="123.68811" f47="128.68564" f48="133.88509" f49="139.29463" f5="24.38039" f50="144.92272" f51="150.77822" f52="156.87031" f53="163.20854" f54="169.80286" f55="176.66363" f56="183.80159" f57="191.22796" f58="198.95439" f59="206.993" f6="25.365462" f60="215.3564" f61="224.05772" f62="233.11061" f63="242.52928" f64="252.3285" f65="262.52365" f66="273.13073" f67="284.16638" f68="295.64792" f69="307.59336" f7="26.390335" f70="320.02145" f71="332.95168" f72="346.40436" f73="360.40058" f74="374.9623" f75="390.11238" f76="405.87459" f77="422.27366" f78="439.33533" f79="457.08635" f8="27.456618" f80="475.5546" f81="494.76904" f82="514.75983" f83="535.55832" f84="557.19717" f85="579.71032" f86="603.1331" f87="627.50226" f88="652.85604" f89="679.23421" f9="28.565982" f90="706.67818" f91="735.23101" f92="764.93748" f93="795.84423" f94="827.99975" f95="861.45448" f96="896.26093" f97="932.4737" f98="970.14963" f99="1009.3478" FilterLength="8191" InterpolateLin="0" 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v94="-0.007085872" v95="-0.0055962752" v96="-0.004380208" v97="-0.0034189047" v98="-0.0026969972" v99="-0.0022144855"
Normalize:ApplyGain="1" PeakLevel="-1" RemoveDcOffset="1" StereoIndependent="0"