I remember being woken up from one of my daily naps by the familiar melody of the ice cream van that comes round our estate every day in summer. True, it was slightly odd that I could hear it so vividly despite wearing ear plugs; nevertheless I leaped out of bed, grabbed my purse and ran outside. Imagine my disappointment when I realized that there was no ice cream van in sight!
Auditory hallucinations are more common that we might think, and they do not only happen to people with mental health problems. The example I described above is a form of hypnopompic hallucinations, i.e. those experienced upon awakening from sleep, and familiar to just over 12% of the population (Ohayon et al., 1996).
Let’s take a moment though to consider what we mean by a ‘hallucination’. The word itself comes from the Latin ‘allucinari’ meaning ‘to wander in the mind’, ‘to dream’ (Choong et al., 2007). It is a perception that occurs in the absence of an external stimulus, when we are fully or partially awake, and is not to be confused with an illusion, which is a misperception of a real stimulus. Hallucinations are one of the cardinal symptoms of schizophrenia; indeed, 70% of people with this illness hear voices. However, they are not the only ones. In some studies 10% of men and 15% of women in the general population described hearing voices at some point in their lives (Tien, 1991). It is not uncommon to experience hallucinations when we are drifting off to sleep (hypnagogic) or when we are waking up (hypnopompic). Hearing voices might affect us even more after we lose a loved one; nearly half of recent widows and widowers hear the voice of their dead spouse (Carlsson and Nilsson, 2007).
What is it then that people hear? Hallucinations could be fragments of memories or stream of consciousness, often related to worries, and are more likely to occur in times of stress or tiredness. The voices could be loud and clear, as if someone in the room has just spoken, or they could be barely distinguishable from our thoughts.
“I hear a mixture of men and women, but no children. They usually tell me to do things, but not dangerous things. Like they’ll tell me to take out the garbage or check the lock on the window or call someone. Sometimes they comment on what I’m doing and whether I’m doing a good job or what I could be doing better.” (Woods et al., 2015).
Since hallucinations affecting healthy people have a similar form to those that torment patients with schizophrenia, scientists think that they are on the continuum of normal perception. Where, then, is the line between ‘normal’ and ‘psychotic’ hallucinations and if we hear voices, does it mean we are at risk of a mental illness? Hallucinations that lead to, or are part of a disorder tend to be more negative and intrusive, and are associated with more anxiety and depression. For example, a healthy person might find spiritual or religious explanation for their voices and is more likely to ‘go along’ with them, whereas a person with psychosis is more likely to think that the voice belongs to a real person and try to resist it. The distress that the voices can cause might create a vicious cycle, where the more the individual fears and tries to avoid the voices, the more intrusive and frightening they become.
“Starting when I was about 20 years old, I heard the voices of demons screaming at me, telling me that I was damned, that God hated me, and that I was going to hell… The voices were so frightening and disruptive that much of the time I was unable to focus or concentrate on anything else.”
The physiological underpinnings of hallucinations are not clear. We know that hearing sounds and voices that are not there activates the auditory cortex in a similar way to ‘real’ auditory stimuli. The content of hallucinations are probably best understood in the context of the individual’s life, personality and experiences. A simple melody produced by the auditory cortex in response to your craving for ice cream is harmless enough. Similarly, hearing the voice of a dead loved one might be comforting; their voice is imprinted on your brain – no wonder it can be reproduced when you long to hear it. Perhaps the derisive commentary is your internal critic that harnessed the auditory cortex to torment you? One thing is certain: whilst voices can be very distressing and coping with them often requires professional help, they are not always dangerous or a sign of mental illness.
Post by: Jadwiga Nazimek
Carlsson, M. E. & Nilsson, I. M. (2007) Bereaved spouses’ adjustment after the patients’ death in palliative care. Palliative and Supportive Care, 5, 397-404.
Choong, C., Hunter, M. D. & Woodruff, P. W. (2007) Auditory hallucinations in those populations that do not suffer from schizophrenia. Current Psychiatry Reports, 9, 206-12.
Johns, L., Kompus, K., Connell, M. et al. (2014) Auditory Verbal Hallucinations in Persons With and Without a Need for Care. Schizophrenia Bulletin 40 (4): 255-264
Nayani, T. H. & David, A. S. (1996) The Auditory Hallucination: a Phenomenological Survey. Psychological Medicine, 26, 179-192.
Ohayon, M. M., Priest, R. G., Caulet, M. & Guilleminault, C. (1996) Hypnagogic and hypnopompic hallucinations: pathological phenomena? British Journal of Psychiatry, 169, 459-67.
Tien, A. Y. (1991) Distributions of hallucinations in the population. Social Psychiatry and Psychiatric Epidemiology, 26, 287-92.
Woods, A., Jones, N., Alderson-Day, B., Callard, F., fernyhough, C. (2015) Experiences of hearing voices: analysis of a novel phenomenological survey. The Lancet. Psychiatry http://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366%2815%2900006-1/fulltext