I expanded the scope (very very slightly) of the openSUSE audio troubleshooting guide, adding a section to cover how to determine which application is using one’s audio device: SDB:AudioTroubleshooting - openSUSE - How to determine app using sound device
I also noted user Jengelh impproved the section on permissions, which is great to see (such helpful inputs): SDB:AudioTroubleshooting - openSUSE - audio permissions