I wouldn’t mind knowing what Audacity is thinking about while it’s doing that.
The document seems to suggest it averages the whole performance and anything prominent or sticking out must be noise.
Am I close?
Also further down, Noise Reduction doesn’t retain that profile and there’s no way to save it?
I see the title is back to Noise Removal now instead of Noise Reduction. The title was switched to Noise Reduction because too many people were trying to remove noise to zero. The current manual does admit that’s probably not the best idea.
The way that the noise profile is created was changed by Paul around the time that the effect’s name was changed from “Removal” to “Reduction”. As far as I’m aware he did not document those changes.
it’s only in the Effect menu itself that you see Noise Removal, the effect itself is still the changed Noise Reduction( a truer description of what it does as you say).
I suspect that when Muse created the structured default effect menu they felt that some if the effects in the Noise Removal are actually capable of “removing” noise, for example Click Removal and Repair.
I think the manual is correct, though it does not go into detail about what is happening “under-the-hood”. Without going deep into a mass of messy code, we just go with the fuzzy idea that the noise profile is a kind of audio fingerprint of the selected audio.
