My new supply of soft silicon earplugs has arrived. For reasons I am not certain of these style of earplugs mostly used by swimmers are marked up in Australia 3 to 4 times the price they retail for overseas, so I source mine from the Earplug superstore USA.
If you dislike regular foam earplugs or find they do not stay put in your ear then consider giving the silicon ones a try. You can get some at any chemist and you should find they do not isolate the rider from sounds as much as foam earplugs but do reduce the wind noise enough to make riding more enjoyable as well as save your hearing. They are also very comfortable unlike foam or in ear molded things, I also use them on airplanes to sleep.