Wanted to let you know that I read this. Don't know that I can give a complete reply right now for it is a great question. But here are a few of my initial thoughts.
If there is a deceiver's voice (and I believe there is,

), then there must be at least two voices. There may even be a third voice if I include my own. So the question becomes how can I distinguish between these two or three voices?
My first reaction is that I would have to compare the three voices (and there may be many others if we consider other voices, such as friends, family, culture, marketing, etc., but for simplicity I recommend that we limit this to just these three). The question then becomes are there characteristics that a "normal" person could recognize and distinguish in such a way as to recognize God's voice, the deceiver's voice, and my own voice?
Let me think about this and get back to you. But, meanwhile, do you have any reaction to my line of reasoning so far?