"Voice of god"

[Captain Scarlet]

There are also such sound machines used by the military, which focuses a narrow beam of sound into a person's ears and makes them hear things, while no one else can hear them.
So, could the voice of God be a similar type of concentrated sound beam that traveled into the ears of the Prophets?
Maybe the sound comes from somewhere in the universe and then it crystallizes into specific words upon entering a person's brain (aka divine revelation)?

Yeah...and maybe the equipment he uses sometimes breaks which is why he needs to send angels to earth to men sitting in caves...