It all depends on your height, the angle of attack of the wind plus the angle of your body for the air to exit. The trick is to have low number of vortexes and genital pressure drops across the helmet.
So, test ride the helmet at highway speeds on the bike you are going to use it with, riding any bike like you stole it noise is the least of your problems.
Another bike, another riding position maybe another helmet?
I have spent 2 weeks salary on helmets, forget they hype and cost, it's what will work for you and when it comes to the test so many variables are beyond manufactures scope, just make sure what ever you buy has a very good strap and locking mechanism.