I have 7 helmets, including a Shoei Qwest full helmet, a Daytona 3/4 helmet, a Bell Mag 9, a couple of flip up helmets, and a couple of half helmets.
In my experience, the difference between which open face helmet is quieter is a moot point. They're all loud. I've ridden with all of them on my Triumph cruiser (which has a quiet parallel twin and stock quiet pipes) with Triumph's "tall" windshield (which is laughable) and there's hardly any difference between open face / 3/4 helmets in terms of wind noise. On the highway I cannot hear my ScalaRider G4 intercom with any of them.
In contrast, the SHOEI Qwest helmet is night and day quieter. I could hear the Intercom fine on the Qwest, but I can still hear wind noise. To be fair, I just got the Burgman and haven't been able to do a comparison between the helmets on it yet. The Mag 9 or equivalent may fit your needs perfectly behind the windshield.
When I'm with my riding buddy and need my G4, I wear the SHOEI. When I'm alone, my go-to helmet is a $49 (I think they're $65 now) Daytona 3/4 helmet and some $0.20 foam earplugs. It's extremely comfortable, light weight, and doesn't seem to be as vulnerable to wind buffeting as my other helmets. Toss in a pair of transitional riding glasses and I'm good to go. The foam earplugs will mitigate wind noise better than any of these helmets could ever do.
http://www.daytonahelmets.com/d.o.t.-ap ... ll-helmets
If I were to buy any other helmet today, I think I'd look at the new Bell Rogue helmet. I haven't decided yet if it's ridiculous looking or really cool looking, but having a half helmet that wears like a 3/4 helmet with a removable face shield and a place to mount your speakers seems like an extremely functional helmet that I'd love to own. Keep the detachable face mask under the seat when it's warm out, and put it on when the weather gets bad. I'm a function over form kind of guy, and logically this helmet is very appealing. I'd also wait a year to get one. I paid full price for the Mag 9 when it came out only to watch it drop $100 in price within a year, and I don't even wear it now.