[dhgeyer]

Helmets, full face or otherwise, do little to reduce wind noise. Some of them even amplify it according to one article I read recently. It seems the helmet actually transmits the vibrations to the skull, or bones behind the ears. At highway speeds you are still at risk for permanent nerve damage, from which you have already had some loss, by your description.

There are two solutions. One is to get a windshield that is tall enough to create a quiet zone around your body and head. This can be tricky, as a windshield that big often causes turbulence on the helmet that can cause your head to get knocked around to a degree that is anywhere from mildly annoying to painful, to, I suspect, damaging. There are countermeasures for this. Slits in the shield itself to allow some upward movement of air sometimes help. Decent sized lowers often help on a cruiser style bike. It can take some fiddling around to get a good windshield setup. A rule of thumb is that you shouldn't be looking through the windshield, but just an inch or two over it in your normal riding position.

The other approach is to use a much smaller windshield, or no windshield, and use earplugs. Most experienced riders use disposable foam types. The ones I use reduce noise by 33 decibels - more than enough to protect your hearing. Even though they are disposable, they can be used multiple times. It's a cheap, easy solution. They won't interfere with your helmet in any way if inserted fully and properly. And they don't, in my experience, interfere with hearing ambient noise (traffic, horns, sirens, etc.) any more than sitting in a car with the windows closed.

Riding around town at speeds under 40 mph, the wind noise isn't really a problem unless it bothers you. It won't create enough noise to cause damage in any case.