When I was a young engineer I worked in an oil refinery and got my share of noise from turbines and all sorts of rotating equipment. Plus I also moonlighted as a professional diver, working recklessly at depths

Motorbike riding with stone age helmets doesn't help either. Add some more time with power tools and you've got a mild but solid case of tinnitus

As 4paws has stated tinnitus is a chronic situation, does not reverse but can get worse over time. In mu opinion here's not one single preventive measure against noise, but a combination of things, like selecting a small windshield that doesn't create turbulence around the helmet, a quiet(streamlined?) helmet, chin skirt and earplugs.
The best earplug I've come across so far is the type which you roll and squeeze between fingers and insert into the ear canal. When done properly it's dead quiet while letting important sounds pass. I have a bunch of those earplugs, because when I worked in north Africa the only transport to Saharan oilfields was twin prop airplanes of various vintages, and as you step aboard the pilots made sure that you picked up a pair, company regulations... Those earplugs work best because they are designed to deaden the noise when a 800 HP engine is two meters away and the prop is almost grazing the fuselage
I'm guessing the frequency of the props at the cruising speed is similar to that of generated by the wind when riding... Anyway they work quite well, I keep a pair in every motorcycle jacket pocket.