Here’s a wild idea : I have three wireless Sonos speakers, one in the office where I’m at, one in an adjoining bedroom and a third in an adjoining bathroom.
I’m in the office - I’d like to flip a switch on my Sonos app and using my phone’s microphone make a rough approximation to balance the volume across those three speakers.
Now if you want to get really crazy, I’d like to have the volume continue to adjust regardless of where I take my phone until I turn it off.