Imagine being deaf and not being able to take your cues from a person speaking to you because a mask shields their mouth. That is why transparent face masks and shields, while costly compared with classic counterparts, could prove a boon for the deaf and hard of hearing in the coronavirus era.The concept has started to take off, aided not least by YouTube tutorials or the likes of American football coach Nic Saban, who makes a point of wearing his to games.Other proponents include the French…