Odd stuff; Discovery (or one of those kinds of channels) had a show on this exact thing; these people would hear these bumps in the night and all; but it turned out to have more to do with these electromagnetic fields.
Could make an interesting tool for PsyOps in certain Persian countries, especially in combination with beamed "voices" that seem to originate inside their heads. "I am the twelfth imam, and Amadinejad is a lying infidel" would be sort of cool.