The Five Senses and Beyond: The Encyclopedia of Perception - Jennifer L. Hellier 2017
Auditory Hallucinations
Auditory hallucinations occur when a person hears sound without external auditory stimulation. This phenomenon is sometimes referred to as paracusia, although paracusia also refers to other disorders involving impaired hearing. Five to 28 percent of the population suffers from auditory hallucinations (de Leede-Smith & Barkus, 2013). Symptoms of auditory hallucinations range from hearing voices to hearing music. Depending on the cause, auditory hallucinations can be treated in a variety of ways with varying success.
History
Auditory hallucinations have been reported throughout human history. Perhaps people who were revered as being in contact with God, or the gods, were experiencing auditory hallucinations. Socrates (ca. 470—399 BCE) may have experienced auditory hallucinations that he referred to as his “daemon” or his “voice of reason.” During the Dark Ages trepanning (drilling a hole in the skull) was used to treat auditory hallucinations. Later in history, those hearing voices might have been tried as witches. Throughout history, auditory hallucinations could land a person in an insane asylum or a sanatorium.
Types and Symptoms
Auditory hallucinations are often associated with schizophrenia and related disorders, yet may occur in mental health disorders such as bipolar disorder, depression with psychotic features, and posttraumatic stress disorder. Auditory hallucinations, however, may have causes other than mental illness.
A variety of medical conditions can cause auditory hallucinations. Patients with temporal lobe epilepsy, for example, may have damage to the temporal cortex of their brain. Some of these patients have auditory hallucinations, and the hallucinations may be a predictor of an impending seizure. Other medical conditions including stroke and migraine can cause auditory hallucinations, as can tumors and infectious diseases. Various forms of stress are also associated with auditory hallucinations including sleep deprivation and drug use.
Dementia patients experience many changes in their ability to perceive their environment. One of the changes some experience is auditory hallucinations. These patients are complex; the patient may be taking medications that contribute to auditory hallucinations, or may be experiencing strokes or migraines that cause auditory hallucinations.
Other auditory hallucinations do not involve hearing voices. Instead, patients hear a range of sounds, from buzzing and tones to complex sounds including music and singing. Single tones including ringing, buzzing, and humming are referred to as tinnitus, whereas complex sounds involving music and singing are called musical ear syndrome (Bauman, 2013).
Treatments
Auditory hallucinations associated with mental health disorders, such as voices heard by patients with schizophrenia, are disruptive to patients’ lives. These hallucinations are treated with a combination of medication and therapy. Treatments are not always effective, so additional treatments are being developed, including transcranial magnetic stimulation (TMS), a technique using low-frequency magnetic fields to reduce brain activity in areas of the brain generating the “voices.”
Auditory hallucinations can be associated with a variety of medical conditions including epilepsy, brain tumors, dementia, drug use, and infectious causes. In order to treat these hallucinations the underlying medical cause must be addressed. Treatments vary widely and may range from surgery to remove a tumor to medical treatment of an infection.
Patients with tinnitus often seek treatment for this condition if it becomes disruptive to their day-to-day lives. The cause of tinnitus must be investigated; many underlying medical conditions cause tinnitus including age-related hearing loss, earwax, and medications. Once the cause has been identified, treatments range from addressing the cause to prescribing hearing aids, introducing white noise, and retraining the brain to mask the tinnitus.
Patients with musical ear syndrome may not seek treatment if the music is not disruptive to everyday life. In the case of patients with hearing loss, some would miss the music if it were to stop. “I mean, where else can you hear beautiful music without wearing hearing aids, assistive devices, iPods, headphones or other paraphernalia?” (Bauman, 2013).
Outcomes of Treatment
The outcome of the treatment of auditory hallucinations depends on the identification and treatment of the underlying cause.
Future Directions
Mechanism of auditory hallucinations remains largely unknown. Future research focusing on the mechanism of these hallucinations will aid in treatments. The auditory hallucinations associated with tinnitus, dementia, and epilepsy may each have a different mechanism than those associated with mental illness. It is important to realize that the presence of auditory hallucinations does not, on its own, indicate mental illness, but auditory hallucinations should be discussed with a health care provider.
Lisa A. Rabe
See also: Age-Related Hearing Loss; Tinnitus
Further Reading
Bauman, Neil. (2013). Musical ear syndrome. Tinnitus Today, Spring 2013. Retrieved from http://ata.org/sites/ata.org/files/pdf/TT_Spring2013_Final.pdf
de Leede-Smith, Saskia, & Emma Barkus. (2013). A comprehensive review of auditory verbal hallucinations: Lifetime prevalence, correlates and mechanisms in healthy and clinical individuals. Frontiers in Human Neuroscience, 7(367). http://dx.doi.org/10.3389/fnhum.2013.00367