Why isn’t there a way to make the bluetooth earplug whistle loudly? It would come in handy every time one misplaces it.
For instance: Start an app on the mobile phone and press a button and the headset makes a sound.

One can also use the strength of the bluetooth signal to at least find out which room(s) it is in.  Maybe one could use a sieve or pan to make the BT signal more directed.

Then evolve this to include glasses, carkeys and whatnot.