I am bringing this thread back to life a little.
I noticed this when I ride as well:
I have a Sena 20S and use the helmet speakers. I've added the various pads to bring the speakers closer to my ears for better sounding audio. However I notice whenever exiting the freeway and slowing down the music gets much louder.
Obviously that's not correct. As speed decreases so does helmet noise. Suddenly I'm hearing how loud the music has been.
I have a Shoei GT Air 2 and the integrated Sena (I think it is an SR2). I am really happy with the speaker placement, sound quality, etc.. The only real complaint is battery life seems to be lacking on a longer rides (maybe 2-3 hours). I just have to top it off when I stop and sometimes I forget.
Anyway, back to the point - I bought some "Decibullz" that were mentioned earlier, specifically the "pro-musician" variant. The custom molding is actually quite cool, I basically shoved them in my ear and pulled my helmet on, so I have a custom ear plug for my helmet/ear. The little filter seems to not impede any noise from my speakers, but claims it protects you from loud noises. I am hoping wind noise is part of that "loud noise".
I will update when I give them a good try out, but I am pretty optimistic about them. Previously every ear plug I tried would snag on the helmet and basically sound like static in my ear, of pull out of place. I have a friend that swears by ear buds, but they always end up hurting my ears. We will see how these do.
Ryan