I have an HJC AC10. I got it because it was the lightest helmet rated by MCN and was rated near the top with the expensive Arai and Shoei models. Any good quality major brand helmet that fits your head the best will be quietest. Arai makes two lines, one for a "round" shaped head, and one for a "elongated" shaped head. (Their descriptions of head shapes). I have had Bell, Shoei and HJC, several models of each, and this AC10 is the best fitting, quietest and lightest yet. MCN said it was as good in construction as the top priced helmets but the graphics were not as good. I checked the Snell and Dot studies on all helmets and the HJC AC 10 had one questionable area about impact, I don't remember just what, but it was not sufficient evidence to deter me, I think it was chin strap. You almost have to pick the one that feels best on your head and then go out on the freeway and see. Cycle Gear let me do that with several helmets.
Mike