I have had Shoei, Bell, HJC and Arai. I changed to Z1R a few years ago because of impact testing results that I believe makes them a better choice. By chance, the Z1R is quieter than any of my previous helmets. On my CBR929, it is quiet enough that earplugs dont make much difference. On the B12S, it was noticably noiser. I wondered why. I concluded the windshield on the 929 directed the air at about mid chest and less air was blowing up, under the helmet.
The B12S shield directed air at aproximately top of shoulder level. I took a dremel with a 1" circular saw and cut the windshield down to aproximately the same height as on my 929. I removed about 3 1/2 inches from the bandit windshield height and the noise level is reduced.
Helmet buffeting is also decreased. Where the airstream strikes you depends on your height, so this may not work for anyone much different than my 5'9" height.
Blue