About half a century ago, I used to bicycle a lot (like 4 mi each way back and forth to work everyday in Manhattan!). And I always wore a Bell helmet. And, yes, a helmet may not save your bacon. But I think a lot of folks after the fact, in instances where a helmet would have helped, might wish in hindsight that they were wearing a helmet if it would help them get some of their brains back. Just like Kev and the unexpected sheep, you never know what’s going to happen. Maybe an unexpected pothole. Maybe you’re riding along besides parked cars on a street and someone you didn’t see sitting in car throws up a driver’s side door and “clotheslines” you. I’ve skidded going downhill on a college campus asphalt walkway when I hit an unexpected gravel patch or when feeling too many oats, cornered too fast to turn tight enough to avoid hitting a sidewalk curb coming out of the turn and took bad tumbles both times. I was glad both times I had a helmet on (doesn’t save your literal skin, though!).
My oldest daughter’s partner is super-athletic (and also about 6’6" and 250 lbs). He was biking a few years ago in London, Ontario on a main street at night doing about 25 to 30 mph. He wore a yellow safety vest. Had flashing lights on himself and his bike and the street was well-lit. A car that didn’t see him pulled out of a side street unexpectedly (he saw the car and thought it was waiting for him to continue on by). When the front of the car hit his bike, he was thrown into the windshield, shattered the windshield on impact but in doing so, ricocheted off the car some distance into the street. He fractured an ankle in multiple places on flying down onto the roadway and somewhere (I forget whether by car or by street impact) had his helmet split in two but suffered no head injuries. His ankle required months of healing and rehab.
So maybe it’s like wearing a mask. Do I have to do it? Is it really going to protect me from the pandemic if it’s not an N-95 mask? etc. Who’s to tell me what I have to do and take away my liberties and my enjoyment of life?! A helmet is relatively cheap insurance compared to the possible (lifetime?) expense of injuries you might endure for not wearing one if the unexpected happens. It may very well not protect you. But if it does save your bacon, you’ll be a happy camper. And so will medical insurers or the government health service for not having to cover your medical expenses.
P.S. Both a Bing and a Google search turn up a number of hits looking for “helmet for cochlear implant” - here’s one for a heavy-duty female bicyclist: Biking with a cochlear implant came about in an unconventional way.. Doesn’t say what brand of helmet but the post is “young” enough that maybe contacting the author could get anyone interested some more info.
Also, a mom who had a special football helmet designed for her son when she gave in to letting him play football (after she realized letting him play baseball with a 60 mph fastball whizzing his way wasn’t that much safer). “I learned there was a company that could design a specialized helmet with the pads situated, so Nicholas could still wear his processors with the helmet on.” https://hearandnow.cochlearamericas.com/hearing-loss/children/pediatric-sensorineural-hearing-loss/