Interface client currently tells audio mixer where it's head is located each frame, for processing in-world audio.
Add a JS call to allow a script to set the location of the head/ears that is sent to the audio mixer.
As needed, make sure that the audio mixer can inject microphone audio at a point different that where the 'ears' are positioned.
Add a test script called fakeEars.js that creates a model of a head in front of you and moves your 'ears' to there. Should be able to talk into the ears on the head and hear yourself.
This will not immediately be released but will be tested extensively once complete.