I looked in ear noise reduction a couple of years ago. I couldn't get past the price and look of Cat-Ears, so I made a pair. Once they're positioned correctly, they work, but mine are also fairly HOT. I saved them for winter cycling but never put them back on. Further research led me to
Slipstreamz - Home out of South Africa. The pricing of the Spoiler was better and the look was unobtrusive. So I bought a pair and put them on. I can say that while they didn't really reduce the overall noise level, they moved it out away from my ears. There is still a wind roar that I can hear but its not the overpowering one in my ear that comes from nothing. In fact I recently replaced my helmet and didn't move the Soilers over until this weekend. They honestly do make a difference but only by reducing the wind noise to a loud background roar rather than an in your ear roar. Would I recommend them? Maybe, they do make it somewhat easier to differentiate between various background noises. For me riding with them is more enjoyable, but as with everything else YMMV.