I would love to hear more about this!
It's just a MEMS mic, a battery, and an ESP32, very simple but it works amazingly well. I wrote a companion Android app for it and it works extremely reliably!
Sneak peek: https://imgz.org/i6xDDz6x/
Thank you, must make one!
Your projects are amazing, saw your site a couple days ago and just saw your submissions now, love it and thanks!