> 10% of people also experience visual disturbances like perceiving visual static, lightning, or flashes of light. Some people may also experience heat, strange

> 10% of people also experience visual disturbances like perceiving visual static, lightning, or flashes of light. Some people may also experience heat, strange feelings in their torso, or a feeling of electrical tinglings that ascends to the head before the auditory hallucinations occur Such phenomena are well known amongst advanced yogis. Sleep scientists would do well to investigate there.