Auditory hallucinations and subvocal speech in schizophrenic patients.

Fourteen of 18 hallucinating schizophrenic patients reported that the voices they heard went away when they undertook a maneuver that precluded subvocalization. The same applied to 18 of 21 normal subjects who hallucinated under the influence of hypnotic suggestion. Control maneuvers had no such effect. The authors suggest that auditory hallucinations may be projections of schizophrenic patients' verbal thoughts, subvocalized due to deficient cerebral cortical inhibition.