Socrates, that irrepressible realist, often heard the voice of his "personal deity", his daimonion, and obeyed it explicitly. It was for this most of all that he was ordered to commit suicide ("corrupting youth" was a trumped-up charge).
The sacred scriptures of every religion, and nearly all of literature prior to the 18th Century, are full of people hearing the voices of muses, angels, demons, and deities.
Poets and other artistic creators speak of Muses such as Erato as inspiring (literally "in-breathing") their work. William Blake, shown here, was one such. [The original image is found at InterVoice, an online resource for people who hear voices.] Another resource for voice-hearers is Hearing Voices Network.
While overly rationalistic scientists, mainly psychologists and psychiatrists, have since the 1800s defined all voice-hearing as pathological, these two organizations are devoted to helping people who may be troubled by the voices they hear; even more, they are forums (fora?) for those who are not troubled by their voices, but by people's reaction to any discussion about them.
These and other resources are mentioned in Muses, Madmen, and Prophets: Rethinking the History, Science, and Meaning of Auditory Hallucinations by Daniel B. Smith. Dan Smith does not hear voices; he tried rather hard to induce the experience, without success. He was motivated (driven?) to study these phenomena because his father and grandfather heard voices very frequently; the former with torment, the latter with thanksgiving for their guidance. He prefers the term "Voice Hearing" rather than "Auditory Hallucination". So do I.
His title is well-chosen. Where voice hearing is not pathological, and sometimes when it does cause harm, it is often considered a divine experience. Mystics, Christian and otherwise, credit God or angels for the messages they hear.
Joan of Arc, seen in this painting by Jules Bastien-Lepage [image from the Metropolitan Museum of Art], took guidance from voices she began to hear at age thirteen. They trained her into the personality that could, at the age of seventeen, impose her will on the Dauphin Charles of France for most of a year. Sadly, her voices did not warn her of an ambush by the English, nor adequately guide her as, in her naivety, she spoke in terms the English clerics could only take as heretical. While fear of being burned prompted her to briefly recant, she soon returned, saying she preferred to die than to deny she had heard from holy saints and from God.
Today, "inner voices" are both feared and considered a joke. If you talk about "hearing things", you'd better be joking, or your closest friends might send for "guys in white jackets".
Because of the influence of psychiatry and its DSM-IV, any voice I might hear while someone right next to me (who is not deaf) cannot hear it, is considered a hallucination, which PsyWeb describes thus:
Hallucination can be auditory, olfactory, visual, or tactile. Hallucinations are false perceptions or unreal apparition. They do not correspond to the stimuli that is present and have no basis in reality. You have to remember that what is an hallucination in one culture, is not in another.Despite the throw-away comment about cultural differences, the authors of the PsyWeb glossary clearly mean to deny any reality to such experiences.
I wonder if any of them is a Lutheran or a Quaker. Both Martin Luther and George Fox heard voices and accepted their guidance. So did Augustine, Thomas Aquinas, and Theresa of Ávila. When Jesus declared "The words that I say to you I do not speak from Myself, but the Father who abides in Me does His works", was "the Father who abides in Me" a hallucination? Was Saul of Tarsus hallucinating when he heard, "Saul, Saul, why do you persecute Me?"? He states that his attendants did not hear the voice, only he did. Were all the Hebrew prophets hallucinators?
Some researchers, such as Julian Jaynes, who wrote The Origin of Consciousness in the Breakdown of the Bicameral Mind, propose that voice hearing was characteristic of the human brain when humans were "pre-conscious": To oversimplify, their right brain acted as an inner deity, giving advice and admonition to the left. This has produced a near-cult movement, the Julian Jaynes Society.
However, the prevailing opinion among non-Theists is that all such experiences are imaginary, that they take place only in the (diseased) brain. If that were true, at least a quarter of us—and I mean us Westerners, the most rationalistic and least spiritual of peoples—are subject to such "diseased" experiences. At least a quarter of Americans have heard a voice speaking that seemed to be outside them. I have, but no more than three or four times.
Author Smith relates how two researchers told blindfolded students (one at a time) they were about to hear "White Christmas", but didn't play the tune. After a half-minute of silence, they'd ask the student to rate the experience. Half reported hearing the song play in their head, and 5% thought they'd actually heard the music play in the room. The students tested had all been screened to make sure none were schizophrenic or otherwise mentally "unusual".
For me, as a Christian mystic, but one with few "exceptional" experiences, I am sympathetic to claims of voice-hearing. I believe both God and angels can speak, and that they have done so. I think it likely that Satan (an angel) and perhaps other evil spirits can also speak. Whether they use sound through the air or some more direct influence, I don't know.
Two lines of evidence lead me to believe that voices can be heard in "unconventional" ways. Firstly, direct brain stimulation with a low-voltage probe can induce recall of memories in full sensory regalia: sight, sound, touch, smell, and/or taste. They can also stimulate seeming sensory experiences that are not memories, including heard speech.
Secondly, a signal such as a spoken message that modulates an ultrasonic carrier wave can be focused tightly, and just the person at the focus will, because of the nonlinearity of the outer and middle ear, "rectify" the signal and hear the message. This could become a way for museums to present educational messages at chosen exhibits, that one hears only if one stands "inside the blue circle" or whatever.
In the book, the author goes into quite a bit of detail about Joan of Arc and Socrates, as poles of a mystical spectrum that is not pathological; perhaps I should say, two corners of a triangle that has pathology at its third corner. I know two psychotic people who hear voices that are in no way beneficial, so I know the experience can be very damaging. But I thank the author of the book, and the two organizations linked above, for promoting the interests of people who find the experience to be salutary.