An auditory hallucination, or paracusia is a form of hallucination that involves perceiving sounds without true auditory stimulus. A common form involves hearing one or more talking voices. This may be associated with psychotic disorders such as schizophrenia or mania, and holds special significance in diagnosing these conditions. However, individuals may hear voices without suffering from diagnosable mental illness. The Hearing Voices Movement is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucination include exploding head syndrome and musical ear syndrome. In the latter, people will hear music playing in their mind, usually songs they are familiar with. Recent reports have also mentioned that it is also possible to get musical hallucinations from listening to music for long periods of time. This can be caused by: lesions on the brain stem also, tumors, encephalitis, or abscesses. Other reasons include hearing loss and epileptic activity. Auditory hallucinations may also result of attempting wake- initiation of lucid dreams