How about adding an "ear-plugs" Wasteland item that they get for free everytime they spawn.
Clicking on "Use" would remove it from the inventory ... Once they have the earplugs on they could use a key to remove the earplugs, and they would appear in the inventory again.
You have to tell them how to remove the ear-plugs ... when they put them on.
Back in Arma 2, Takistan Life: Revolution, we had "cell-phones" which were free for players when they spawned. Something interesting happened ... people started committing suicide so the could get a new "cell-phone" and sell it at the stores. It was a really slow way of making money, but some people did it because they had a store right across the civilian spawn location. We also saw that the map soon was littered with cell-phone items that players dropped when they died (more objects, slower server). So we ended up making the "cell-phone" not drop, and also making it have $0 re-sale value.
