For the first time in a long time some process (Teams ehem, ehem, ...) was making some annoying sound and there was no way to stop it. So, I decided to restart the sound system.
The problem? Fedora switched from pulseaudio to pipewire Fedora 34 plans to use PipeWire for sound instead of PulseAudio. The net is plenty of information about
restarting sound subsystem referring to pulseaudio.
Once I've discovered this change, it has been easy to discover the way to restar it and I'm documenting it here, just in case it is useful for somebody. You can type, as user (no sudo needed):
systemctl --user restart pipewire^C
And you're done: the annoying sound disappeared.