Reddit reviews Generic Peltor Comtac I/II ARC Adapter/Tactical Helmet Rail Suspension Headset Support

You can buy arc rail adapters like this

They should work with something like these

They can be worn under the helmet, just have the headband go between the two top cushions inside of the helmet shell. They are also supposedly compatible with Peltor style ARC adapters, somehow. I can't confirm the adapter compatibility personally, but from what i've seen you can just pull the metal rods out of the connectors that attach to the ear cups, and then replace them with the adapter's rods.