I find it annoying when I forget to stop videos before closing my laptop and then having sound played when opening it in public.
I tried to add a script to /lib/systemd/system-sleep:
#!/bin/bash amixer -q -D pulse sset Master mute echo 2 >> /home/user/test
The script seems to be called when suspending as new lines are being appended to the "test" file (twice - which might indicate that the script also runs on resume - can someone confirm this assumption?)
Either the sound system re-enables itself automatically or something else is wrong. But the amixer command executed manually works fine.