Hearing voices is a common type of auditory hallucination. Hallucinations are sensations or perceptions that occur in a wakeful state and seem real, but are created by the brain. Overall, auditory hallucinations are the most common type of hallucination. These can include familiar sounds, unusual noises, even human voices. The voices in auditory hallucinations can be pleasant or threatening.
Hearing voices can be associated with some psychiatric disorders or medical conditions. Psychiatric conditions associated with hearing voices include bipolar disorder, psychotic depression, schizoid and schizotypal personality disorders, and schizophrenia. Medical conditions affecting the central nervous system, such as brain tumors, delirium, dementia, epilepsy and other seizure disorders, and stroke, can be associated with hearing voices. Voices may also be associated with high fevers.
Some people abuse certain substances because those items can cause hallucinations, including hearing voices. Auditory and other hallucinations can also be associated with other substances, such as alcohol, when used in large quantities or during withdrawal. They can also be a side effect of some medications and may occur with hearing loss, sleep deprivation, or severe fatigue.