I have a bucket load of those small google home mini devices (the old revision).
It would be very cool to be able to piggyback on the already existing microphone on the google device.
Using this as a binary sensor along with a PIR sensor would make for a more stable presence detection.
Anyone know if this is even possible ?
I dont intend on spying on the actual sound coming from the google unit in my kitchen eg.
simply being able to measure the amount of noise/sound obtained from the mic. would be sufficient.
I guess google does not expose this possibility.
would be cool though 
I could always add a MIC sensor to my ESPHOME projects… sigh.