Sleep Paralysis (SP) and its associated hypnagogic and hypnopompic hallucinations, along with cataplexy and daytime sleepiness, have traditionally been considered among the “narcoleptic tetrad.”

Psychiatry. A hallucination is a perception in the absence of an external stimulus that has the qualities of a real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space. Hallucination is a combination of 2 conscious states of brain wakefulness and REM sleep. [1]

The two main types of auditory hallucinations are verbal (hearing voices) and hearing sounds or noises. Auditory verbal hallucinations (hearing voices) An auditory verbal hallucination is the phenomenon of hearing voices in the absence of any speaker.