An old joke puts its thus, "when a man speaks to a god its prayer , when a god speaks to a man its schizophrenia"... Many people hear voices without suffering any of the debilitating and dysfunctional effects associated with schizophrenia, some treat these as sources of inspiration of develop religious ideas around them, others become mediums or occultists.
"The Apophenion: A Chaos Magick Paradigm". Book by Peter J. Carroll, 2008.