Let me mention a related issue and a possible solution to this one. I'm very deaf. The nature of it is that, even with a hearing aid, conversation, even in ideal circumstances, is nearly impossible. The level of sound is increased, but not the clarity needed to understand. But I partially lip-read. I've had to ask doctors to remove their masks in consultations, though we step well away from one another. Only then can I understand their instructions.
For many people and in many situations, mask or other face coverings can't or won't be removed. And some people just have learned to speak very softly, for whatever reason.
But, written communication can help. If electronic mediation is possible, students can type questions and responses, perhaps even anonymously.
An instructor in a face-to-face situation can carry a few index cards, perhaps, that can be give to students to write out questions, or whatever.
But there are also microphones that can be employed. There is one kind that feeds directly (bluetooth) into a hearing aid. It can be handed to a student that has a question (face-to-face).
So, old (paper) and new (electronic) tech can be used to mitigate issues, including the one raised by the OP, but also beyond that.
I don't know enough about cultural norms to know whether the request to speak up would be interpreted as insulting. I can't answer the question here directly, but suggest that you need to explore those norms if you really want to keep "connected" to your students.