Last time I looked a Helmets I was pulling away the removeable inside linning and looking at the polystyrene ( or whatever its made from ) inner core that protects whats left of our brains. On the full face helments it came all the way down into ear/cheek area. On the flip face helmets it stopped short of there. Just the outer shell with some open cell foam cheek pads, etc. But no core material in the area where the ear is. I assume to allow for the flip mechanism's. -- That was my guess as to why most the time the Flip Face are noisier than the Full Face. I agree with the above, just throwing out an observation I made on the 2-3 brands I looked at, at the one store. 2003 Concours, 51K COG #6953 IBA 28004 http://mysite.verizon.net/slybones/Concours/connieMain.htmI can say that my Nolan N102E is quieter than my HJC full face was. Funny considering that people say that modular (flip face) helmets are noisier than full face. As people here have said, it depends on the fit and the quality as well as the environment the helmet is in.