Auditory hallucinations are sound-based hallucinations that frequently occur inside the minds of people with the mental disorder schizophrenia, and also occur inside the minds of some psychologically healthy people. In schizophrenic individuals, the presence of these hallucinations can effectively block genuine sound input from the outside world and contribute significantly to the break with reality that characterizes the disorder. According to the results of a study released in April 2013 by Norway’s University of Bergen, people with schizophrenia can potentially gain substantial control over their auditory hallucinations with the help of a simple sound-based training technique.
Auditory Hallucination Basics
There are two basic categories of auditory hallucinations, which scientists generally refer to as true hallucinations and pseudohallucinations. True hallucinations occur when the brain misinterprets or misidentifies sounds that originate in the affected individual’s surrounding environment. Conversely, pseudohallucinations (i.e., false hallucinations) occur when the affected individual hears sounds that don’t come from the surrounding physical environment, but instead originate within the brain. Generally speaking, people with schizophrenia develop auditory pseudohallucinations, which typically take the form of internal voices that “speak” and do such things as carry on dialogues, issue instructions or orders, or otherwise try to guide behavior. Healthy people subject to auditory hallucinations also commonly experience pseudohallucinations, although these hallucinations don’t contribute to any type of significant loss of contact with reality.
Along with fixated, irrational thought patterns called delusions, hallucinations form the primary symptoms of psychosis in people affected by schizophrenia and certain other schizophrenia-related conditions. In schizophrenic populations, auditory hallucinations (technically pseudohallucinations) occur more often than hallucinations involving any one of the other four senses. Typically, the voices heard during these hallucinations seem completely real to the individual. In fact, they commonly take on such prominence that they effectively block out the voices of other people and become central to the everyday experiences of schizophrenic people.
Hallucinations in Healthy People
Roughly 2 percent to 3 percent of psychologically healthy adults in the U.S. regularly experience auditory hallucinations, the authors of a 2007 study review in the Hearing Journal report. In elderly populations, these types of hallucinations may occur as much as 10 times more frequently. Just like schizophrenics and people dealing with other types of mental illness, psychologically healthy individuals frequently experience pseudohallucinations that originate in the brain, although they may also experience true hallucinations. As in schizophrenics, auditory pseudohallucinations in healthy people usually appear as voices that issue instructions or hold dialogues. However, healthy people may also experience pseudohallucinations that manifest as simple unusual sounds or complex pieces of music.
Controlling Auditory Hallucinations
The authors of the study published by the University of Bergen began their work by reviewing the findings of 23 previous studies that examined the ways in which auditory hallucinations affect schizophrenics and psychologically health individuals. After completing this review, they concluded that people with schizophrenia experience two brain events that contribute to the disorder’s ability to rupture a firm connection with reality. First, under the influence of internal voices, the brains of schizophrenics experience a spike in activity in the area dedicated to sound processing. This spike makes the hallucinated voices seem real; at the same time, it essentially disrupts the brain’s ability to track voices coming from outside the body and stops the brain from assessing these genuine voices as real. In combination, these two events orient the schizophrenic mind inward and sharply diminish the importance of the outside world.
Psychologically healthy individuals who hear voices have the ability to control those voices and distinguish them from outside communications with other people. Critically, schizophrenics lack this ability. As part of their work, the University of Bergen researchers created a simple technique to help people with schizophrenia improve their hallucination control. Through headphones, patients were simultaneously exposed to two streams of speech, one of which appears in each ear. Gradually, they learn how to focus on only one of these streams, while ignoring the other. This approach does not eliminate the internal voices associated with auditory hallucinations; instead, it gives the individual an improved ability to ignore those voices and orient his or her mind to the external environment. In order to spread the use of this technique, the study’s authors have created a software application that can be used on commonly available devices such as cell phones and tablets.