Features of professional hearing loss with combined exposure to noise and vibration

Abstract

For most modern industries, there is characteristic the simultaneous impact of noise with other factors aggravating its effect.
 The purpose of the study is to determine the features of occupational hearing loss in the combined effects 
 of noise and vibration.
 Materials and methods. A comparative assessment of the level of occupational risk and audiometric indicators was carried out in three groups of employees: 1st group (210 people) — is exposed to noise, 2nd group 
 (170 people) — to noise and local vibration, 3rd group (200 people) — to noise and general vibration.
 Results. In group 1 workers exposed to isolated noise, occupational hearing loss was diagnosed significantly less frequently compared to group 2 and 3 including workers exposed to combined noise and vibration 
 (7% vs. 14 and 13%, respectively, p < 0.05). Combined exposure to noise and vibration increases the risk of occupational hearing loss by 1.82–1.85 times (RR = 1.82–1.85; EF = 45–46%). Audiological features 
 of the lesion of the auditory analyzer have been revealed depending on the presence and nature of the affecting vibration, manifested by changes in hearing thresholds in certain frequency spectra and their combination. According to the data of speech audiometry, a violation of speech intelligibility with the presence of speech-tonal dissociation was revealed in workers of groups 2 and 3, indicating violations in the central department 
 of the auditory analyzer.
 Limitations of the study. The study is limited to the study of the features of occupational hearing loss in the combined effects of noise and vibration in mining workers according to audiometric indicators.
 Conclusion. The conducted studies have shown the need to develop individual programs for the preservation of hearing, taking into account the degree of risk and the identified features of the formation of occupational hearing loss. The topic of research on the effects of noise and vibration on hearing loss requires in-depth research, taking into account the intensity and duration of vibration exposure, the type of vibration generating equipment.