Ask HN: How to isolate a single voice in JavaScript?

I am making a 2 player game where each player uses their phone as a microphone. It works well when players don't talk at the same time, but there is a big problem when players are talking simultaneously. It turns out the iPhone microphone is really good at picking up everyone's voice who is in the same room.

My AudioConstraints has echoCancellation: true and noiseSuppression: true, but I think those are built for a different purpose.

Any ideas on how to solve this?