I'm getting the same sound but it seems to be coming from the fuse panel.Prima Edizione #44.
When I shut off the engine (push button in off mode), I notice a high pitch electronic tone that persists for a minute or so, and then shuts off. Any clue what this sound is? Anybody else notice it? It's probably on the upper end of frequency that most of us can hear, so the sound might be there even if you can't hear it.