I receive an error message suddenly every time I try to apply the noise reduction to remove a crackle, I restarted Audacity with no help, it still says something like : “sample rate must match the noise profile rate” , it’s basic wav file, ??
The Noise Reduction effect is a 2 step effect. First you create a “profile” of the noise, then you run the effect a second time to remove sound that matches the profile.
For best results the noise profile should be taken from a “silent” (noise only) part of the track that you wish to remove the noise from.
If not from the same track, the noise profile must at least be taken from a track which has very similar noise, and is in the same format as the track that you want to remove noise from. Taking the noise profile from the actual track that you wish to process is the recommended method.
In short - make a new noise profile from “silence” (noise only) in the track that you wish to remove noise from.
For more information, see: http://manual.audacityteam.org/o/man/noise_reduction.html
How do I change the sample rate for noise reduction to match the sample rate of the recording
The noise profile should normally come from the file you’re trying to noise-reduce so the sample rate will already be the same. The noise profile should come from that file because that’s the noise you’re trying to reduce.
IVe never tried this, but if you really want to use a different file make a new noise-file with the same sample rate as your main file. (Change the sample rate in the lower left, export, and open the file with the matching sample rate.)