I've made a command to do this already, but I feel it would probably work faster, if it was built into VA, and I think it's an extremely useful command, that many people would take advantage of if they had it as a option.
I use a desktop mic, and I made a command that drops the system audio down when I Push to Talk. So, I could be watching a video on my computer, and want VA to run a command, I just hit Push to Talk, and the volume drops, and VA can hear me without the video causing VA to run random commands.
Give a option to do this on the Global Hotkey, and allow people to set how low the sound needs to be for them. So if they want the sound to drop to say, 5%, VA will do that, and then return the volume back to whatever it was before.
This is a very handy command, and thought I would ask.