@likelyjanlukas
Something that I've come across that you might be interested in: https://forgedair.co/
It's a hybrid elastomeric respirator (with optional safety glass attachment) that has sound transparency comparable to N95. I've picked one up, with N99 filters, and it's pretty comfortable, on par with the usual 3M respirators. They're working on a P100 as well. It's designed for industrial/fabrication/welding, hence the low profile and optional eye shield, but the rating is the same as other medical respirators.
The main benefit, I think, is that since it uses a large filter medium, it would be more easily customizable, and would generate far less echo than a classic elastomeric, with your amplifier system. I've yet to try it out at work yet, but it seems pretty solid, although I don't think that it'll be much less material waste, as the filter medium is essential a 3M Aura.