Not commenting on the other parts of this discussion but a single shot from a rifle absolutely CAN cause permanent hearing damage. Even some weapons suppressed are still loud enough to damage your hearing over a short amount of time/multiple shoots. Have you ever seen or watched news of cops shooting someone and NOT firing multiple rounds?
Of all the tactical battle rattle these ICE dorks are wearing to capture people, I think suppressors are the least worrisome; should maybe even be mandatory for law enforcement in urban environments. That’s coming from my experience shooting in the Marines and being a hobby shooter since then.