Actually, it isn't that hard a problem technically, you just need a directional mic. I'm deaf, I have NHS issued equipment, and I have a specific setting that makes the mics more directional. Additionally (slightly off topic for the reply, but perhaps of interest) I also have the option of using a discreet wireless mic about the size of a pencap that I can give to presenters or pass round the table. Again, NHS issued, for which I'm very grateful.