It really bugs me when people talk with their mouth covered, whether it's with a veil or a scarf or a surgical mask or their hand. I'm not Deaf in any way, but I find it very very difficult to focus on audio input alone. I avoid phone conversations in favour of face-to-face or email conversations for this reason. I reckon there's nothing wrong with politely *asking* people to remove a face-covering, especially if you are prepared to give a reason why. If you don't ask, you don't get - and by the same token, they don't know that it's causing you problems unless you tell them. I don't know many Muslims personally, but those I do know would be horrified if they thought they were doing something that caused another person real difficulty. If you were stomping back to your ambulance saying "well if you're wearing a niqab I'm not going to treat you, so there!" it would be a different matter entirely. The pity is that there is a reactionary, extremist minority who seem to be acting like this is the case, and getting the perfectly reasonable majority of Muslims a bad name.