Just now thinking about this. I can’t just save a “room tone” segment and export it for use later as a Noise Reduction profile because it will have dither added to it.
What’s the recommendation?
Koz
Turn off dither.
– Bill
Export the noise sample as 32-bit float.
It would be jolly nice if Audacity could save a noise profile for you - better still if it could save several named ones - for redeployment later
(cf. store EQ curves).
Peter.
It would be jolly nice if Audacity could save a noise profile
What he said.
Koz
Turn off dither.
I know you can’t do that. The dither is there to prevent re-sampling distortion. Catch 22.
32 Float is good. I didn’t think of that.
Koz
How would you handle the fact that noise profiles only work for one specific sample rate?
only work for one specific sample rate?
Error message?
I know it’s a valid concern, but how many people do you know that switch sample rates enough times to worry about it? Are we in “that one time the vicar’s wife…” territory?
Koz
Ha ha - I only ever work at one sample rate 
Peter
Just about everyone that work primarily with “files” rather than “recordings”. We have a lot of users that rarely if ever make recordings themselves.
While free downloaded files are usually 44100 Hz, there are many that are higher or lower than that. For example, take a quick look at a few samples on the popular site freesound.org and you’ll see a vast range of sample rates.