The occurrence of MES has been suggested to be very high among the hearing impaired through acquired deafness or the ear condition known as
tinnitus. Though exact causation is uncertain, it has been theorized that the "release phenomenon" is taken into effect. The "release phenomenon" says that individuals with acquired deafness may experience musical hallucinations because of the lack of stimulation, which can give room for the brain to interpret internal sounds as being external. Sufferers typically hear music or singing and the condition is more common in women. The hallucinatory experiences differ from that commonly experienced in
psychotic disorders although there may be some overlap. The most important distinction is the realization that the hallucinations are not real.
Delusional beliefs associated with the hallucinations may occur, but some degree of insight should be preserved. There should not be any other psychotic symptoms present, especially hallucinations in other modalities. Due to the high correlation with hearing loss, MES is common in the elderly due to their often depreciating hearing abilities. == History ==