Hi,
I checked the reference : https://krpano.com/plugins/soundinterface/#stopallsounds
- stopallsounds(false) stops all sounds coming from the soundinterface plugin
- stopallsounds(true) stops all sounds coming from the soundinterface plugin and from the videoplayer plugin
But stopallsounds(true) never works on my side, the only way I can achieve video mute is by manually looping all my video hotspots and setting their muted attribute to true. 
Plus I'm wondering... is there a reverse action to resumeallsounds once we have stopped them?
Thanks