I have a voicemail that I’d like to edit to reduce background noise. Is that possible with Audacity?
A cautious yes.
Effect > Noise Reduction.
It works in two steps. Drag-select some part of the speech that you know is pure noise. No voice. Effect > Noise Reduction > Profile.
Then select the whole file with the Select button on the left. Effect > Noise Reduction > Choose the settings > OK.
Start with the default settings of 12, 6, 3.
See how it turns out.
A cautious yes because what people normally want when they post this question is how to turn complete trash into a voice. Audacity won’t do that. You have to already be half-way good before you start. Another common version of this question is how to turn a bad far-side Zoom interview into a clear voice. Audacity won’t do that, either.
Koz