1. The experiences termed auditory hallucinations are individual experiences, which require to be resolved into many factors.2. To investigate auditory hallucinations more precisely audiometer examinations of 100 cases with auditory hallucinations were made.3. Of these 100 cases there were 31 cases of deafness, 19 toxic deafness, 10 catarrhal deafness, and 2 nerve deafness.4. Of the 19 cases of toxic deafness, 18 patients gave a history of a definite toxic factor, 16 alcoholism, 1 drug addiction, 1 toxemia with a septic infection of the throat.5. No evidence of auditory hyperæsthesia was noted.6. It was noted that the occurrence of an auditory hallucination during the audiometer examination interfered with the response of the patient.The author wishes to express his appreciation to Dr. C. MacFie Campbell for his assistance in preparation of the paper, and to Dr. Leon E. White for his cooperation in interpretation of the otologic and audiometer findings.Abstract Teaser