In this study a comprehensive audiometry was applied to detect the hearing loss in 400 patients (531 ears) with difficult-to-test hearing loss induced by ear or skull injury. It was found that the real PTA detectable rate reached 95.29% and the incidence of hearing loss was 82.11%, of which 68.81% were related to injury. The incidence of nonorganic deafness was 77.59%, i.e., the incidence of hearing loss exaggerated by patients was 57.25% (tested ears), simulated deafness was 16.20% and functional deafness was 4.14%. The principle of dealing with nonorganic deafness was discussed.