If you an oldish am radio. You can set it on the handle of the door and hear the signals communicating if anyone gets really bored and try’s it. I thought it was cool to hear. Especially if you walk up with the wrong key, the car kind of “barks” at it.
Could hear a scritchy sound a split second after each button push on the fob, either lock or unlock. Tune to AM dial, between stations.
You can also lock the doors and than wait a few seconds, and as you walk up to the car, watch the little red LEDon the fob, it will flash as you get close, and you will hear the communication.
This is a low tech way of testing the door oscillators. It does the same for the rear hatch, with the exception that it doesn’t start trying to communicate with the key until the button is pushed on the hatch.