Spacial/Directional Voice for Multiplayer Rift Demos

[CaptnYesterday]

Any other Rift Devs given thought to this challenge?
(I apologize if this is covered somewhere)

NPCs and effects are simple and the engine takes care of the directional/spacial sound & voice. What about in-game player voice chat?
A good way to explain the goal is to ref the current system in Borderlands 2. NPC voice is directional and volume dynamic until you walk too far away. Before becoming inaudible, NPC voice changes over over to a comm system. Putting this in place for a multiplayer VR demo is my goal.

Challenges:
-Directional voice source
-Dynamic proximity based volume
-Change over to 'Comm' style system when speaker/listener distance passes a threshold.

-I think in-game integrated voice chat will be required for the above and going forward with VR. Not sure about others but I usually used skype, teamspeak, ventrilo.

Solutions:
-Found (not tested) a Unity Assest called uSpeak that features 'Directional sound'. The feature is not made for VR but as an extra for immersion. https://www.assetstore.unity3d.com/#/content/4639
-Anyone know a good implementation for any specific engines?