I ended up owning 9 helmets. Shoei, Arai, HJC, Scorpion, Bell, and Vemar. There really is not much difference in quality or long term durability. If I had to rate them, like that, the top helmet might be a 96, the lowest, a 92.
Two things I've learned. One is, if the helmet is intended, or marketed as a "race" helmet, its been designed to wear by a rider using low bars. It can be very quiet when your head is aimed that way, but raise up as you would for higher bars, and its noisy. Thats the shoei x 11 and x 12. With this bike, a sport touring or touring cut will be better.
The best helmet I have is easy to mention. I tried one on in a motorcycle shop in a small Idaho town. I never considered their brand before. When I put it on, it was slightly snug, but I knew it would break in over the next few rides and be perfect. It felt like it was made for me. It is the Bell Revolver Evo.
If you find a brand , with YOUR kind of fit, it will be pretty quiet, for YOU. None are really quiet enough to not use ear plugs.
They are all made the same way. They protect your head with material like they make the cheap 7-11 camping coolers with. Then they protect the styrofoam with a hard coating, paint it, and charge you.
From our only testing program, you see dollars spent does not mean added safety. SHARP Helmets - THE HELMET SAFETY SCHEME
So, heres my guide to owning one and not having to buy 9.
If its super comfortable , in the shop, its too large. Drop down one size to where its slightly too tight. 99% chance to not listen to who is selling it to you. Cycle Gear used to let you return a used helmet, but most dont. Usually stores will keep up sizing you, but comfort will come later. You really want something halfway uncomfortable. If you hit 100mph and the shin strap holds the lid on, you are wearing a size to large. Sometimes two sizes.
Dont feel bad about removing the cheek pads for a test fit. If that top part fits well, you can buy different cheek pads for a custom fit.
Dont get sold on one brand. I like HJC. They are reasonably priced, look good, and everyone has them. However, their large is too large, their medium is too small..for me, so I cant wear their brand.
Arai and Shoei and any other high end helmet are great, but they have to fit you to be any good at all.