https://www.minidsp.com/applications/usb-mic-array/acoustic-...
Lmk if anyone has any questions about it! It’s android-only, but I’ve gotten an agent to write a Mac version of it though haven’t tested yet.
eBay link to what I bought: https://www.ebay.com/itm/960060893216
In my case it identified that the likely beep was about every 62 seconds pretty quickly - then I confirmed that one of the recordings was the mystery sound and it locked in from there.