The article covers data on wide prevalence of occupational neuro-sensory deafness in Russian Federation where nowadays three major deafness classifications are applied, international, for noise-related occupations and for medical and social examination. The authors analyzed present classifications of deafness, emphasized positive and negative aspects of each classification from occupational medicine viewpoint. Several classifications applied at the same time complicate professional activity of specialists solving diagnostic, occupational and social problems of patients with occupational deafness and result in conflicts. Advantage of the classification for noise-related occupations is that it enables to evaluate premorbid deafness, since early signs of ear alteration due to noise, and even slight negative changes in hearing could be addressed by specialists (as stages and degrees cover 10 dB differences), however review of audiometric assessment is necessary for noise-related occupations. To increase efficiency of ENT-specialists work in diagnosis and prevention of occupational neuro-sensory deafness, legal and methodic basis should be developed.