The author summarizes data pertaining to conditions for development of impaired hearing due to long-term action of noise. Noise acts on the human organism in several regions. In addition to hearing damage disorders of vegetative and psychic functions develop. The acoustic cell is affected by prologed noise in four stages: adaptation, acoustic fatigue, acoustic exhaustion and atrophy of the acoustic cell. Deterioration of acoustic cell function and their organic damage leads to a defect of the sensorineural basocochlear type. During audiometric evaluation of hearing in people exposed to noise we use four sets of values: type of hearing defect, general trend of the defect, dynamics of progression and „watch“ frequency. So far it is not possible to differentiate prospectively a noise resistant and a noise sensitive subject. Therefore audiometric screening is necessary to enable us to take appropriate preventive measures already during the first signs of increased and excessive noise-conditioned acoustic damage.

        Key words: noise, impaired hearing, prevention