Why i don't hear the wind, when the ear faces it? When I ride a bike, a hear the wind with both of my ears. But if I turn my headto the side, the front ear doesnt hear it. Does it have to do with how ear is built, or with eardrums vibrations? Couldn't find the answer in Google.
 A: You don't hear the wind itself, as its frequency is way too low. What you do hear is local turbulence that caused by the wind. The wind stream hits objects close to your ear (mostly the tragus, but also concha, pinna, head, helmet straps) and that scambles up the air molecules and makes them move fast. That's the turbulence you actually hear.
The amount of turbulence is a function of the air speed and the gradient of the air speed. Both are very high when the wind is passing the side of your head, they are much lower if you face the ear into the wind, since the head acts like a "wind break".
Similar effect: If you hold a piece of paper out the window of a driving car, it's going to flail around like crazy. If you put it on the wind shield, it will lay fairly still. 
A: Because the wind direction is null when facing the ear. 
Your head makes the wind go left and right. And as the wind doesn’t flow “through” your head, at the middle it doesn’t flow not in, our, left nor right. So speed cancels out.
As here 
https goo.gl/images/esUL3K
