In the end, Stone did acquire a set of earmuffs for the pair that had been keyed to each other. This meant, apparently, that they wouldn't block out the sounds produced by whoever was wearing the partner set. They were warned that this did mean excessive noise generated by one of the two would still be a problem of the other.
"So, you don't NEED to put these on but I've got them now and even managed to find a paired set. This should work the best for your job because it'd be bad if you couldn't communicate with each other during combat." Explained Stone.
"Thanks!" said Kamiko cheerily putting them around her arm for the time being while Kat set hers around her sash for a second before immediately hitting them with her arm. *Seems Kamiko had the better idea here. I thought the gap would be a bit wide for keeping on our arms but seems to hold mostly strong. Not sure HOW considering how slippery our skin can be when it wants.*