 Using anodal cathodal tDCS the investigators aimed to treat auditory hallucinations, a symptoms of schizophrenia. The investigators plan to apply tDCS such that it can simultaneously increased activity in the frontal brain areas and reduce activity over temporoparietal cortex, 2 areas involved in the physiopathology of the disease. Real active stimulation will be compare to a sham condition in 60 patients 30 in each group. 30 patients will be included in a French center Hospital le Vinatier, sponsor of the study and 30 in Tunisia laboratory vulnerability to psychosis Pr Gaha à Monastir. 