Noise coming from every wheel - bearings?

Hello,

as the weather got hotter, I have started to drive with my windows half-down when driving through city for short distances, otherwise I use AC. What I noticed about one month ago was the noise coming from the wheels when going over bumps. It is really annoying and sounds like when you shake metal balls in a pocket. Firstly I thought that it was coming from the brake calipers, so I replaced all the shims (actually, I have replaced rotors and pads also as they were pretty rusty and I got a good price on them). However, the noise is still there. Yesterday I got my tires replaced for the summer ones and as I was checking afterwards if the bolts are tightened correctly, I noticed that if I shake the wheel (really hard) then I can replicate the noise.
To have it summarized.
What I have tried already: Replaced rotors, pads and shims on every wheel and ensured that all of the bolts are tightened correctly. And I have also googled about this problem but every finding was about the shims not fitted correctly.
What are the symptoms: Strange metallic noise coming from the wheel (every) when going over road surfaces that are not perfectly flat and with windows down (when they are all up, I cannot hear anything). I can replicate the noise if I shake the wheel (with car on the ground).
I have taken video of the noise and hope you car hear it, but I think it is pretty noticeable. It sounds like the bolts are really loose but I have ensured 10 times that they are tightened and also as I wrote previously the noise is coming from every wheel. You cannot see it on the video but I'm filming with one hand and shaking the wheel with another (pretty hard), that's why the whole video is shaking.

Thank you for any advice.

 

± 110 000

 

These are definitely not the dust covers, I gave special attention and inspected them when I was doing the brake job. This must be something different as it is occurring on every wheel. The noise is exactly as bearing balls but if that is the case I would notice it on the steering or something... or am I wrong?

 

Classic_pri: As from today I'll be travelling next 2 weeks and therefore I will not have access to my Prius. I will try that afterwards.

bisco: Neither do I.. At first I thought the exhaust got loose at some point but after I shaked the wheel I could clearly hear that it is coming from the part where bearing is placed. The car is steady, and the steering wheel also, even at speeds over 100mph, I guess I would notice the bearings somehow. Prius is year 2006 and I own it for 8 months now as a second owner.

 

I had time today, so I've decided to play with my Prii and solve problems that I have postponed.
I have lifted the car and shake the wheels holding them on 3 and 9 o'clock and 12 and 6 o'clock and everything was perfect [nothing loose or strange noises]. However when I shook it, the same metallic sound appeared so I unscrewed the nuts and when I placed the nut on the road I heard the sound - washer!
After that everything was clear. I looked at the holes on the wheel and they were too tight to fit the nut, so the whole wheel was hold by 5 nuts that were just 2 threads tightened. O - M - G
I have separate wheels for winter, that's why I haven't noticed the noise [holes on them are enough wide to fit the nuts] before. I'm really glad that it is finally solved without any injures. Lucky me