electrical noise under the hood

there's a well sustained electrical noise under the hood. I hear it only after I shut down the car.

I'm a second owner of an 05. before hitting 20k, i have never heard this sound. its a presistent electronic pur that I can usually count on hearing everytime I get out of the car, but there have been some cases when it's silent.

Im not sure if this is a problem that I should escalate to the DS or if its just a natural occurance. Its not bothersome and I dont notice anything else wrong with the vehicle. I am a bit concerned because I have been driving it a lot harder than usual. I average 40-45 right now where I used to be 50-55.
I just a read an article about the consequences of driving hybrids too hard, so now i think I'll be a little more patient on the road. Lately, Ive been hearing a lot about the perception that hybrids are too slow and I cant hlep but to prove people wrong when I get the chance I mean, has anybody gone 100 mph on this thing!? Its such a smooth ride!

 

hmm...well it is kind of like a "whirring" . but like i said, this sound seems new to me. Its not soft, infact its pretty loud and lasts for a minute. I get the feeling that it is coming from under the hood. Maybe sounds will get louder as the car ages or I just start paying more attention to them.

hopefully, its just a natural thing for the car to do. :huh: