John
John is a free and open-source noise-reduction plug-in for Linux. It is available as VST3 and LV2 and supports mono and stereo audio.
This plug-in has many names. Some favorites are John, Annp (Apfeltaschh noise reduction plugin), Suam? (Shut up around me?), and Ha-dee-eff.
Play a section that contains only noise and turn on Learn noise. Turn it off before the wanted signal starts, then set Reduction from 0 to 30 dB.
