Alright, I came up with this idea while playing today!
Why not make VoiceChat available only when you're in the Ghost Hud.
With the Ghost you can still run around, so if players want to chat, they pull their ghosts.
I could meet a player in the wilderness while on patrol and simply pull my ghost and talk to them!
This would even make the Sitting Option really useful if you can sit in a circle and talk to eachother while your ghost is active!
And if you don't need VoiceChat you simply put the Ghost back in your bag as you do now while looking for quests!
This would be the easiest solution and maybe even innovative in terms of VoiceChat!