Recent right front passenger whirring sound sporadic

I'm trying to trouble-shoot so I can discuss with the mechanic. Also need to know if I should go to the Toyota garage or the general repair we've used for other repairs. Our 2008 Prius has a little more than 73000 miles on it, mostly town driving. Recently, I heard a whirring sound between 35-45 mph. The noise is almost melodic. The first time I heard it, I thought it was coming from my grandson's toy gun, but they are all out of the car now and I still heard the noise. I heard it first about 2 weeks ago, then nothing for a week. and then more frequently last week. It seems to happen on turns or turning. I'm thinking brakes, or power steering, maybe bearings or a tire out of round (I have run over a curb recently). I haven't had brakes put on the car and I've heard that chirping noise indicating they should be changed. I thought it might be the power steering pump, but from this forum, I learned there isn't one on a Prius .Safety is a concern, since I take the grandkids around. I appreciate any advice. Thank you.