I devised a quick, homemade fix:

1. cut out a couple of pieces of cardboard, 3" in length (as long as necessary to block the length of your ears), 1.5" in width.

2. fold lengthwise at a 90 degree angle

3. tape the shorter length securely along the front chin strap of your helmet. The cardboard edge should extend outward at approx. 90 degrees, blocking your ears completely

4. voila! enjoy a huge reduction in wind noise!

5. cost: free, as long as you have some old scraps of cardboard lying around and any kind of adhesive: tape or glue. I prefer tape for easy removal.

I could see someone artistically inclined creating a nice, stylish pair of cat ears or something similar.