How to edit volume settings on rooted android manually?

[AC Question]

Hey guys I was just wondering what directory and what file one needs to be edit in order to mute the phone manually on any android phone e.g. note 5. I would like to know on a phone that is unrooted how you can tell if a phone is muted by looking at the files within a directory e.g. System > etc > firmware or maybe build.prop show something I cannot see, maybe its somewhere completely different. Any insight would be appreciated.