All of the following are features of hallucinations, except :
Hallucination is a sensory perception without external stimulation of the relevant sensory organ. Though there is no stimulation of sensory organs, hallucinations appear to arise from one of the external sensory organ.
It is independent of the will of the observer
Sensory organs are not involved
It is as vivid as that in a true sense perception
It occurs in the absence of a perceptual stimulus