The Scientific Journals

By : Bettina Thraenhardt

Auditory hallucinations are not always disparaging. They can also be encouraging, such as when a voice whispers, “Come on, you can do it!” or “It really wasn’t your fault.”

In fact, auditory hallucinations may not be uncommon. Because it is diffi cult to defi ne the phenomenon with true precision, data on its prevalence differ from study to study. As early as 1983, though, psychologists Thomas B. Posey and Mary E. Losch, then both at Murray State University in Kentucky, found that roughly 70 percent of the 375 college students they questioned admitted to having heard voices at least once. Subjects thought that they had heard deceased relatives, divine beings or their own thoughts. Still others had heard their names, often before falling asleep. Acoustic perceptions during waking or presleep phases—reported by 40 percent of Posey and Losch’s subjects—are generally viewed as pseudohallucinations. Thus, by including them in their tallies, these researchers may have produced a high estimate.

Nevertheless, in 1991 a National Institute of Mental Health survey found that nearly 5 percent of the 15,000 American adults who responded had experienced hallucinations—most of them auditory—during a one-year period; only one third of that group also met criteria for a psychiatric diagnosis. According to Thomas Bock, a psychotherapist and director of the outpatient psychosis service at the University Medical Center of  Hamburg-Eppendorf, Germany, at least 3 to 5 percent of the population in western Europe and the U.S. hear voices. Schizophrenia, in comparison, affects only about one in 100.


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