So this thread got me to thinking, usually very dangerous but not this time, and I taped a piece of house door weather striping to my helmet. You know, that self adhesive gray foam stuff that comes in a roll. I used a piece that was about 3/4" wide and 1/2" tall and about 10 or so inches long. Using a pair of scissors I put a taper to the front edge of it and left the back side alone. I taped it on a couple of inches behind the upper most part of the helmet. Just a WAG.
What an unbelievable difference! My helmet for whatever reason happens to be super loud. I can never ride without ear plugs. This piece of foam reduced the noise by about 2/3!
Of course the down side is it's pretty ugly but I just consider that a match to the rider. I think I'll try to find something that looks a little better and play around with the placement to see if I can get even more out of it.
Thanks for the thread