Because in sandstorm we already have new key bind use 3dvoice to talk each other whatever teammates or enemys
We don't need system force people nearby to use 3d voip,people can choose what kind of talk function they want,like ARMA3. Of course sametime enemy still can be hear if they use radio talk or 3dvoice talk to their teammate.
That will be an true improvement after insurgency2 voicetalk system.