Hello, Audacity 2.3.0 here.
I use Noise Reduction mostly for removing my turntable’s typical vinyl noise when transferring my library and since that noise is pretty consistent I’m wondering if I have to capture a new Noise Profile every time I work on a new file or does Audacity remember the last Profile I captured on a previous file? And, by extension, does it remember the Noise Profile after the application is restarted?
Yes you can use the same noise profile for multiple files. However, the noise profile is critical to the effectiveness of Noise Reduction. A “similar” but “not quite the same” noise profile is likely to work to some degree, but making a new noise profile each time is likely to be more effective.
No. The noise profile is not retained after closing Audacity.
It would be possible for Audacity to have that ability as a “new feature”, though personally I have reservations about such a feature. Taking the time to locate a good, representative noise sample, can pay big dividends in the quality of the final result.
You might want to try what is suggested at Step 8 in this workflow tutorial: https://manual.audacityteam.org/man/sample_workflow_for_lp_digitization.html
And that is to use the High Pass Filter effect.
It seems to loose the profile, but you can do the experiment just as easily as me or someone else… If “OK” is greyed-out there is no stored profile.
The noise is usually different on each record/recording so it’s probably best to use a new profile on each record. (I usually combine the sides and “process” the album as one long file before splitting into individual songs.)
If you’re not already doing this, the Click Removal and & Repair effects can be helpful with vinyl clicks & pops.
Or there is other [u]specialized software[/u]. I have [u]Wave Repair[/u] ($30 USD) and [u]Wave Corrector[/u] (now FREE!). I’ve used Wave Repair for a long time. It has several different repair methods and does an audibly-perfect job removing most (but not all) clicks & pops. And, it only “touches” the audio where you identify a defect. The downside to that is that it usually takes me a full weekend to fix-up a recording. Wave Corrector works automatically, but I’ve only used it a couple of times.
The noise profile is not retained after closing Audacity.
I think I’m on record as wanting the ability to save the profile somehow. You know eventually, you’re going to hit the edit job with no place to grab the profile and whose sound is the same as a sister shoot. I wouldn’t mind an extra step to prevent New Users from thinking Noise Reduction doesn’t need a profile step at all.
Use Last Profile?
But also, as a legacy Sound Soap user, you don’t need the profile step, you can average the existing sound and other tricks.
Thanks to all the replies, good stuff.