Great minds think alike. I was going to post something about Jaynes. I figured no else even remembered him but I was wrong.
He never really dug into that subject in "Bicameral mind"...
Obviously, Abraham and the Israelites believed they were hearing the voice of the Creator, Jehovah. But what about the rest of humanity? Were they hearing the voices of the Sons of God (watchers)? Were they hearing the voices of the Fallen Angels?