[philsnow]

It's a setting that AFAICT only shows up in facetime. When I'm in a facetime call, in the control center there's a new "mic mode" tile (next to the also-facetime-only "video effects" tile that toggles portrait mode). In the mic mode panel there's three options "Standard", "Voice Isolation", and "Wide Spectrum".

I use the voice isolation one and people I've talked to say that it's drastically improved the call quality, particularly while I'm walking next to a busy street.

edit: you can see the setting without actually starting a call, just go into the facetime app and hit "New FaceTime". It will show you a blurred front view camera and let you pick a contact to call, but at that moment you can drag the control center down and they'll be there.

[happyopossum]

It shows up when you’re on most voice calls - I just tested it in Google Meet, and it works in zoom too from past experience.