Hallucinations are neither a mental illness nor a psychological disorder, but a psychiatric symptom, mostly seen in psychiatric disorders such as schizophrenia, but also in local lesions of the brain such as tumours, trauma, bleeding, or reactions to drugs or medication, and when the mind is over-stimulated. Phantom hearing is an illusory auditory sensation in which the patient hears voices that do not exist and is one of the most common hallucinations in psychiatric practice.
Patients hear voices that can be verbal, such as comments, praise, insults, reprimands or orders, or non-verbal, such as the roar of machinery, the sound of running water, birds chirping, etc.