Here's my take, for whatever it might be worth.
The shockwave from a bullet (especially a rifle round or bigger) would create a shockwave effect when flying by an object (a person for this case). Unless it is a subsonic round being fired from a suppressed firearm, the bullet will be traveling faster than the speed of sound. So if it flies closely (note the word "closely") by the person's head then it can [a] send a high amount of pressure into the person's ear causing ringing and temporary hearing loss, and in high frequency (multiple bullets flying by) cause a bit of disorientation. The disorientation can also be caused by the ear pressure because our ears help with our balance. It would be a minor effect unless we're talking about an MG42/MG34 blasing next to our ear. But the trick is this: the bullets would have to fly by the head because that's the one place where all of our senses meet.