text: Unless you are talking about statistics, I'm pretty sure you mean "medium". In fact, God does not "speak" at all. When people are said to have received direct communication from the Almighty, it is actually the Voice of God that does the talking. Not the voice of God, as in God's voice, but the Voice of God. This role was filled, I believe, by the archangel Metatron.\nThe reason for having a Voice of God is that when God says things, they are things like LET THERE BE LIGHT; not things that are appropriate for human ears. When He needs to say something like "I am what I am," He does so via the Metatron.\n\nNote: this answer is based on, and is consistent with, a lot of research into Judeo-Christian theology; not on personal belief.