By "quiet helmet", I'm assuming you're referring to wind noise, correct? I think this is a legit question. Depending on how windy it is outside, sometimes the wind noise rushing past your ears can get annoying. I personally don't like anything in my ears (like ear-buds) as your ears are your first line of defense in safety.

Unfortunately, I don't have any advice as far as which helmets might be quieter in this regard as I don't think wind noise into your ears is a design concern for helmet manufacturers. Years ago there was a company that made little triangle shaped covers you could attach to your helmet straps that would not only quiet wind noise but also kept cold air out of your ears. My ears literally ache in colder temperatures if I don't cover them. Unfortunately, these little covers apparently didn't sell as they are no longer available. I've considered crafting my own as I think they were a good idea.

This post has a few of the available wind blocking devices, of which it sounds like the OP has already tried something similar:
https://gearforventure.com/bicycle-h...ar-protection/