Brief noise minutes after shutoff??

If I happen to stay in my car a few minutes after I shut it off, I hear this brief - say 0.25 second - crank noise. The sound is like a hybrid of (see what I did there?) the sound made by pulling fast on a handbrake (emergency brake) in an old (and pathetic) Chevy Chevette and the jarring sound of grinding the starter on a car that's already running, but more muted. I don't have a problem otherwise, but I hope to figure this out before the certified used warranty runs out on my 2012 Prius Three with around 50K miles.

I just dropped off my vehicle at the dealer for diagnosis and I didn't think to record audio. This is my first PriusChat post, so if I should post somewhere else etc., let me know.

 

Thanks for the replies, folks!!

I don't have much mechanical expertise, but MG1 turning the crankshaft seems to fit the scenario. I'm going to read up on on that. It's not a "loud" noise but sometimes it's louder than others. Maybe it just depends on how far the parts have to travel to get into position. The variation is what made me wonder if the noise is ever a sign of trouble (e.g. if it gets louder).

;-) I would love to see the look on the dealer service advisor's face if I brought my car in and said "I think there's something wrong with my car. I don't hear a few clicks, a squirty sound, and a kind of a buzz and a blower-y sound when my car is off."
They must have run long with my recall-related firmware update yesterday. He said they didn't hear anything and wondered if I was talking about the 'pin moving into place when I put it into park'.

Makes me wonder if I need to put a hidden camera on this thing and see what else it does when I'm not around!