AiPods Pro 2 make "Ultrasonic" sounds after being put away

Every time I put away my AirPods Pro 2 (put them from my ears into the case and leave the case at my desk) they seem to emit something I'd call an "ultrasonic" sound.

It's kind of like the sound emitted by Apple Watch after exiting water mode, just way more pitched up.

I wanted to add that it reminds me of Google Tone but that extension is dead now (yet another Google product lol) so I can't confirm.

Is this sound part of Find My, or does it have a different function?