For the PHP Internals News podcast, I used a set of noise cancellation filters, which worked wonders. I had a look around on the Internet, and learned that there is a LADSPA Noise Suppressor for Voice plugin. Some Linux distributions have a package for this LADSPA Noise Suppressor for Voice, but my Debian distribution bookworm does not. It turns out that this plugin uses neural networks to cancel the noise. Noise data is also available there.