I’ve looked at suggestions on StackExchange and made some changes to files in /etc but after each login or reboot it is up to 100 % again in pavucontrol. On this computer I hardly ever use the speakers, and I want the microphone muted, always, so I guess I could even block list a few kernel modules for sound (which ones ?). But why can a desktop user not easily turn volume to zero, forever ?
Edit : Thanks all. It was not StackExchange but on AskUbuntu from where I tried some suggestions. I also tried muting audio in Pavucontrol but that didn’t help between logouts and logins. Now I have set the default audio device in Pavucontrol to Dummy, and that works. I can still play sound from a video in VLC, but the microphone keeps muted.
Sure. The solution was already in the edit part in the post. The solution that worked for me was to switch to Dummy in Pavucontrol.
Thank you, when I last viewed it, the title was changed to solved, but I did not see the edit. Cheers!