Hallucinations

by Oliver Sacks

  Various explanations have been offered for why people hear voices, and different ones may apply in different circumstances. It seems likely, for example, that the predominantly hostile or persecuting voices of psychosis have a very different basis from the hearing of one’s own name called in an empty house; and that this again is different in origin from the voices which come in emergencies or desperate situations.

  Auditory hallucinations may be associated with abnormal activation of the primary auditory cortex; this is a subject which needs much more investigation not only in those with psychosis but in the population at large—the vast majority of studies so far have examined only auditory hallucinations in psychiatric patients.

  Some researchers have proposed that auditory hallucinations result from a failure to recognize internally generated speech as one’s own (or perhaps it stems from a cross-activation with the auditory areas so that what most of us experience as our own thoughts becomes “voiced”).

  Perhaps there is some sort of physiological barrier or inhibition that normally prevents most of us from “hearing” such inner voices as external. Perhaps that barrier is somehow breached or undeveloped in those who do hear constant voices. Perhaps, however, one should invert the question—and ask why most of us do not hear voices. Julian Jaynes, in his influential 1976 book, The Origin of Consciousness in the Breakdown of the Bicameral Mind, speculated that, not so long ago, all humans heard voices—generated internally, from the right hemisphere of the brain, but perceived (by the left hemisphere) as if external, and taken as direct communications from the gods. Sometime around 1000 B.C., Jaynes proposed, with the rise of modern consciousness, the voices became internalized and recognized as our own.5

  Others have proposed that auditory hallucinations may come from an abnormal attention to the subvocal stream which accompanies verbal thinking. It is clear that “hearing voices” and “auditory hallucinations” are terms that cover a variety of different phenomena.

  While voices carry meaning—whether this is trivial or portentous—some auditory hallucinations consist of little more than odd noises. Probably the most common of these are classified as tinnitus, an almost nonstop hissing or ringing sound that often goes with hearing loss, and may be intolerably loud at times.

  Hearing noises—hummings, mutterings, twitterings, rappings, rustlings, ringings, muffled voices—is commonly associated with hearing problems, and this may be aggravated by many factors, including delirium, dementia, toxins, or stress. When medical residents, for example, are on call for long periods, sleep deprivation may produce a variety of hallucinations involving any sensory modality. One young neurologist wrote to me that after being on call for more than thirty hours, he would hear the hospital’s telemetry and ventilator alarms, and sometimes after arriving home he kept hallucinating the phone ringing.6

  Although musical phrases or songs may be heard along with voices or other noises, a great many people “hear” only music or musical phrases. Musical hallucinations may arise from a stroke, a tumor, an aneurysm, an infectious disease, a neurodegenerative process, or toxic or metabolic disturbances. Hallucinations in such situations usually disappear as soon as the provocative cause is treated or subsides.7

  Sometimes it is difficult to pinpoint a particular cause for musical hallucinations, but in the predominantly geriatric population I work with, by far the commonest cause of musical hallucination is hearing loss or deafness—and here the hallucinations may be stubbornly persistent, even if the hearing is improved by hearing aids or cochlear implants. Diane G. wrote to me:

  I have had tinnitus as far back as I can remember. It is present almost 24/7 and is very high pitched. It sounds exactly like how cicadas sound when they come in droves back on Long Island in the summer. Sometime in the last year [I also became aware of] the music playing in my head. I kept hearing Bing Crosby, friends and orchestra singing “White Christmas” over and over. I thought it was coming from a radio playing in another room until I eliminated all possibilities of outside input. It went on for days, and I quickly discovered that I could not turn it off or vary the volume. But I could vary the lyrics, speed and harmonies with practice. Since that time I get the music almost daily, usually toward evenings and at times so loud that it interferes with my hearing conversations. The music is always melodies that I am familiar with such as hymns, favorites from years of piano playing and songs from early memories. They always have the lyrics.…

  To add to this cacophony, I now have started hearing a third level of sound at the same time that sounds like someone is listening to talk radio or TV in another room. I get a constant running of voices, male and female, complete with realistic pauses, inflections and increases and decreases in volume. I just can’t understand their words.

  Diane has had progressive hearing loss since childhood, and she is unusual in that she has hallucinations of both music and conversation.8

  There is a wide range in the quality of individual musical hallucinations—sometimes they are soft, sometimes disturbingly loud; sometimes simple, sometimes complex—but there are certain characteristics common to all of them. First and foremost, they are perceptual in quality and seem to emanate from an external source; in this way they are distinct from imagery (even “earworms,” the often annoying, repetitious musical imagery that most of us are prone to from time to time). People with musical hallucinations will often search for an external cause—a radio, a neighbor’s television, a band in the street—and only when they fail to find any such external source do they realize that the source must be in themselves. Thus they may liken it to a tape recorder or an iPod in the brain, something mechanical and autonomous, not a controllable, integral part of the self.

  That there should be something like this in one’s head arouses bewilderment and, not infrequently, fear—fear that one is going mad or that the phantom music may be a sign of a tumor, a stroke, or a dementia. Such fears often inhibit people from acknowledging that they have hallucinations; perhaps for this reason musical hallucinations have long been considered rare—but it is now realized that this is far from the case.9

  Musical hallucinations can intrude upon and even overwhelm perception; like tinnitus, they can be so loud as to make it impossible to hear someone speak (imagery almost never competes with perception in this way).

  Musical hallucinations often appear suddenly, with no apparent trigger. Frequently, however, they follow a tinnitus or an external noise (like the drone of a plane engine or a lawn mower), the hearing of real music, or anything suggestive of a particular piece or style of music. Sometimes they are triggered by external associations, as with one patient of mine who, whenever she passed a French bakery, would hear the song “Alouette, gentille alouette.”

  Some people have musical hallucinations virtually nonstop, while others have them only intermittently. The hallucinated music is usually familiar (though not always liked; thus one of my patients hallucinated Nazi marching songs from his youth, which terrified him). It may be vocal or instrumental, classical or popular, but it is most often music heard in the patient’s early years. Occasionally, patients may hear “meaningless phrases and patterns,” as one of my correspondents, a gifted musician, put it.

  Hallucinated music can be very detailed, so that every note in a piece, every instrument in an orchestra, is distinctly heard. Such detail and accuracy is often astonishing to the hallucinator, who may be scarcely able, normally, to hold a simple tune in his head, let alone an elaborate choral or instrumental composition. (Perhaps there is an analogy here to the extreme clarity and unusual detail which characterize many visual hallucinations.) Often a single theme, perhaps only a few bars, is hallucinated again and again, like a skipping record. One patient of mine heard part of “O Come, All Ye Faithful” nineteen and a half times in ten minutes (her husband timed this) and was tormented by never hearing the entire hymn. Hallucinatory music can wax slowly in intensity and then slowly wane, but it may also come on suddenly full blast in mid-bar
and then stop with equal suddenness (like a switch turned on and off, patients often comment). Some patients may sing along with their musical hallucinations; others ignore them—it makes no difference. Musical hallucinations continue in their own way, irrespective of whether one attends to them or not. And they can continue, pursuing their own course, even if one is listening to or playing something else. Thus Gordon B., a violinist, sometimes hallucinated a piece of music while he was actually performing an entirely different piece at a concert.

  Musical hallucinations tend to spread. A familiar tune, an old song, may start the process; this is likely to be joined, over a period of days or weeks, by another song, and then another, until a whole repertoire of hallucinatory music has been built up. And this repertoire itself tends to change—one tune will drop out, and another will replace it. One cannot voluntarily start or stop the hallucinations, though some people may be able, on occasion, to replace one piece of hallucinated music with another. Thus one man who said he had “an intracranial jukebox” found that he could switch at will from one “record” to another, provided there was some similarity of style or rhythm, though he could not turn on or turn off the “jukebox” as a whole.

  Prolonged silence or auditory monotony may also cause auditory hallucinations; I have had patients report experiencing these while on meditation retreats or on a long sea voyage. Jessica K., a young woman with no hearing loss, wrote to me that her hallucinations come with auditory monotony:

  In the presence of white noise such as running water or a central air conditioning system, I frequently hear music or voices. I hear it distinctly (and in the early days, often went searching for the radio that must have been left on in another room), but in the instance of music with lyrics or voices (which always sound like a talk radio program or something, not real conversation) I never hear it well enough to distinguish the words. I never hear these things unless they are “embedded,” so to speak, in white noise, and only if there are not other competing sounds.

  Musical hallucinations seem to be less common in children, but one boy I have seen, Michael, has had them since the age of five or six. His music is nonstop and overwhelming, and it often prevents him focusing on anything else. Much more often, musical hallucinations are acquired at a later age—unlike hearing voices, which seems, in those who have it, to begin in early childhood and to last a lifetime.

  Some people with persistent musical hallucinations find them tormenting, but most people accommodate and learn to live with the music forced on them, and a few even come to enjoy their internal music and may feel it as an enrichment of life. Ivy L., a lively and articulate eighty-five-year-old, has had some visual hallucinations related to her macular degeneration, and some musical and auditory hallucinations stemming from her hearing impairment. Mrs. L. wrote to me:

  In 2008 my doctor prescribed paroxetine for what she called depression and I called sadness. I had moved from St. Louis to Massachusetts after my husband died. A week after starting paroxetine, while watching the Olympics, I was surprised to hear languid music with the men’s swim races. When I turned off the TV, the music continued and has been present virtually every waking minute since.

  When the music began, a doctor gave me Zyprexa as a possible aid. That brought a visual hallucination of a murky, bubbling brown ceiling at night. A second prescription gave me hallucinations of lovely, transparent tropical plants growing in my bathroom. So I quit taking these prescriptions and the visual hallucinations ceased. The music continued.

  I do not simply “recall” these songs. The music playing in the house is as loud and clear as any CD or concert. The volume increases in a large space such as a supermarket. The music has no singers or words. I have never heard “voices” but once heard my name called urgently, while I was dozing.

  There was a short time when I “heard” doorbells, phones, and alarm clocks ring although none were ringing. I no longer experience these. In addition to music, at times I hear katydids, sparrows, or the sound of a large truck idling at my right side.

  During all these experiences, I am fully aware that they are not real. I continue to function, managing my accounts and finances, moving my residence, taking care of my household. I speak coherently while experiencing these aural and visual disturbances. My memory is quite accurate, except for the occasional misplaced paper.

  I can “enter” a melody I think of or have one triggered by a phrase, but I cannot stop the aural hallucinations. So I cannot stop the “piano” in the coat closet, the “clarinet” in the living room ceiling, the endless “God Bless America”s, or waking up to “Good Night, Irene.” But I manage.

  PET and fMRI scanning have shown that musical hallucination, like actual musical perception, is associated with the activation of an extensive network involving many areas of the brain—auditory areas, motor cortex, visual areas, basal ganglia, cerebellum, hippocampi, and amygdala. (Music calls upon many more areas of the brain than any other activity—one reason why music therapy is useful for such a wide variety of conditions.) This musical network can be stimulated directly, on occasion, as by a focal epilepsy, a fever, or delirium, but what seems to occur in most cases of musical hallucinations is a release of activity in the musical network when normally operative inhibitions or constraints are weakened. The commonest cause of such a release is auditory deprivation or deafness. In this way, the musical hallucinations of the elderly deaf are analogous to the visual hallucinations of Charles Bonnet syndrome.

  But although the musical hallucinations of deafness and the visual hallucinations of CBS may be akin physiologically, they have great differences phenomenologically, and these reflect the very different nature of our visual worlds and our musical worlds—differences evident in the ways we perceive, recollect, or imagine them. We are not given an already made, preassembled visual world; we have to construct our own visual world as best we can. This construction entails analysis and synthesis at many functional levels in the brain, starting with perception of lines and angles and orientation in the occipital cortex. At higher levels, in the inferotemporal cortex, the “elements” of visual perception are of a more complex sort, appropriate for the analysis and recognition of natural scenes, objects, animal and plant forms, letters, and faces. Complex visual hallucinations entail the putting together of such elements, an act of assemblage, and these assemblages are continually permuted, disassembled, and reassembled.

  Musical hallucinations are quite different. With music, although there are separate functional systems for perceiving pitch, timbre, rhythm, etc., the musical networks of the brain work together, and pieces cannot be significantly altered in melodic contour or tempo or rhythm without losing their musical identity. We apprehend a piece of music as a whole. Whatever the initial processes of musical perception and memory may be, once a piece of music is known, it is retained not as an assemblage of individual elements but as a completed procedure or performance; music is performed by the mind/brain whenever it is recollected; and this is also so when it erupts spontaneously, whether as an earworm or as a hallucination.

  1. The real patients, however, were more observant. “You’re not crazy,” said one. “You’re a journalist or a professor.”

  2. Freud was not unsympathetic to the notion of telepathy; his “Psychoanalysis and Telepathy” was written in 1921, though published only posthumously.

  3. Recently, a number of people who hear voices have organized networks in various countries asserting their “right” to hear voices, to have them respected and not dismissed as trivial or pathological. This movement and its significance are discussed by Ivan Leudar and Philip Thomas in their book Voices of Reason, Voices of Madness and by Sandra Escher and Marius Romme in their 2012 review of the subject.

  4. Judith Weissman, in her book Of Two Minds: Poets Who Hear Voices, presents strong evidence, drawn especially from what poets themselves have said, that many of them, from Homer to Yeats, have been inspired by true auditory vocal hallucinations, not just metap
horical voices.

  5. Jaynes thought that there might be a reversion to “bicamerality” in schizophrenia and some other conditions. Some psychiatrists (such as Nasrallah, 1985) favor this idea or, at the least, the idea that the hallucinatory voices in schizophrenia emanate from the right side of the brain but are not recognized as one’s own, and are thus perceived as alien.

  6. Sarah Lipman has noted, in her blog (www.reallysarahsyndication.com), the phenomenon of “phantom rings” as people imagine or hallucinate the ringing of their cell phones. She links this to a state of vigilance, expectation, or anxiety, as when she thinks she may hear a knock at the door or her baby crying. “Part of my consciousness,” she wrote to me, “is straining to monitor for the sound. It seems to me that it is this hyper-alert state that generates the phantom sounds.”

  7. There may be paroxysmal musical hallucinations during temporal lobe seizures. But in such cases, the musical hallucinations have a fixed and invariable format; they appear along with other symptoms (perhaps visual or olfactory hallucinations or a sense of déjà vu) and at no other time. If the seizures can be controlled medically or surgically, the epileptic music will cease.

  8. Most people who get musical hallucinations are elderly and somewhat deaf; it is not unusual for them to be treated as if demented, psychotic, or imbecilic. Jean G. was hospitalized after she had an apparent heart attack, and a few days later, she began “hearing a male choir in the distance as if it were coming through the woods.” (Several years later, when she wrote to me, she still heard this, especially in times of stress or when she was extremely tired.) But, she said, “I quickly stopped talking about this type of music when faced with a nurse asking me, ‘Do you know your name? Do you know what day this is?’ I responded back, ‘Yes, I know what day this is—it is the day I am going home.’ ”