Which is not true about hallucination -

Characteristics of Hallucinations:- The absence of corresponding external perceptual stimuli Vividness, force and the real value of normal perception. The experience occurs spontaneously It cannot be produced or terminated at will by subject (not in conscious or voluntary control). Perceived as being in external objective space. Have relative permanency (i.e. remain constant and unchanged). Hallucinations are usually experienced alongside and simultaneously with normal perception.