I will share a solution that I pursued which I think provides the highest levels of both sound quality and ear care: custom-molded earplugs.
Before I lay out the details of the approach, I will note the two biggest drawbacks:
1. It's expensive. Probably $300+
2. With some helmets, putting the helmet on over the slightly bulky custom earplugs can be a little tricky
If you can live with those drawbacks, this can be a very effective solution. Also, I did this five years ago before the new AirPod Pro era. Maybe an AirPod Pro style approach works even better.
The main drawback of plain earbuds is that they never perfectly fit your ear canal. So they inevitably permit a certain (sometimes substantial) amount of wind noise to pass. If you want to listen to music in this situation, you are obligated to turn up the volume on your music so that it's loud enough to be heard
over the wind noise. Now you are assaulting those poor, fragile little cilia inside your ear with two competing sources of loud noise. A test for this: When you come to a stop on the bike, does the music sound surprisingly loud? Another test: Note the volume level that you set your music to when riding, then listen at that same level at home in the quiet of your living room. Does it sound surprisingly loud?
Custom-molded earbuds completely seal with your ear canal, so very little sound passes through other than your music. As a result, you should be able to experience the same level of music intensity at a lower volume. Win-win for your ears.
Custom-molded earbuds - one way to do it:
Step 1: Choose your custom-molded sleeve vendor. I went with Avery Sound. There are other vendors doing similar work.
http://www.averysound.com
http://www.sensaphonics.com
http://www.bigearinc.com
Step 2: Choose an earbud make and model that your custom sleeve vendor supports. I went with the Shure SE215.
http://www.amazon.com/Shure-SE215-K-Isolating-Earphones-MicroDriver/dp/B004PNZFZ8
Step 3: Buy the earbuds, order the sleeve from your vendor.
Step 4: Schedule an appointment with a local audiologist who will create the impressions (molds) of your ears necessary to make the fitted sleeves. This is the hardest step to this point because this isn't necessarily a common request. You might need to make a few phone calls before you find a local shop that understands what it is you want. When you call an audiologist, you'll want to ask them something like: "I would like to have standard ear impressions made of my ears so that I can mail the impressions to a vendor who will be making custom earbuds for me. Do you do that sort of thing?" The guys at Avery Sound swear the going rate for ear impressions is about $30. My experience in Oregon was that it was typically quoted in the $75-$100 range. I paid $80. Also, you will likely need to wait two to four weeks before they have an opening -- after which you need to mail the impressions to your vendor. So, it might be a month from the time you start this project until you have your fancy new custom-molded earbuds.
Step 5: If you purchase the kind of earbuds I did, you will need to remove the stock sleeves before you can attach your custom molds. A "sleeve" in this context is the little rubber plug on the end of the earbud that interfaces with your ear.
Nobody else seems to have had this problem, but I broke two separate nozzles trying to remove the sleeve from my right earbud. Both were replaced without complaint by Shure, but still it was a hassle and added more weeks to the process. If you go with the "freezing" tip suggested here:
https://service.shure.com/s/article/removing-earphone-sleeves
...I might suggest
pulling the sleeve rather than twisting it like I did.
Step 6: Shove your de-sleeved nozzles into your fancy new custom-molded silicone sleeves. The Shure's have a weird rotational orientation and none of us are familiar with the topology of our ear folds, so it's easy to get disoriented with the assembly. Here are a couple photos for reference, both are for the assembled left earbud with custom-molded sleeve:
Step 7: Jam the things into your ears. Doing this is a little like putting in contacts for the first time. It takes a bit of practice. There are how-tos on-line. This is likely Rock bait, but I should probably mention the usefulness of a lubricant. A little bit (don't overdo it) is very useful and helps improve both the comfort
and the sound seal. Remember, I was throwing money at this problem, so I just spent the $8 on the absurd little bottle marketed for this very purpose (Oto-Ease Earmold Lubricant):
amazon.com: Oto-Ease lubricant 0.5 ounce: Health & Personal Care
The most valuable aspect of that purchase was the tiny application bottle.
So, soup to nuts, the complete shopping list for a Sena setup looks like something like this:
Sena SMH10 Bluetooth Headset ($160)
Sena SMHA303 Helmet Clamp Kit for Earbuds ($40)
Shure SE215 Earbuds ($100)
Custom Molded Earpiece Set from Avery Sound ($140)
Ear impressions from local audiologist ($80)
TOTAL $520
If you don't want to go the Sena route or already have that gear, you can knock the first two items off the list and shave $200 off the total price.
