Iran Occupational Health

  Background and aims: Exposure to excessive noise is a serious threat to the health of industrial workers' hearing. This is a study of hearing problems among workers in the sugar cane industry in Khoozestan Province.

  Methods: In this descriptive-analytical study, the hearing status of 265 employees, including workers in different sectors and administrative employees, was checked in terms of the rate of left and right ear hearing loss in octave frequencies (500 - 6000 Hz) using an eudiometry machine. In addition to those factorswhich affect the hearing loss such as work experience and age, special attention was given to noise as a cause of hearing loss. The results were compared with different related standards.

  Results : The collected data were analyzed by means of SPSS and R programs. Initially, descriptive statistics were computed, and then the formulas for t-test, analysis of variance (ANOVA), and linear regression analysis were run in order to complete the study. Drivers and operators of agricultural machinery and industrial machinery that are exposed to 90 and 85 dB noise levels, respectively, havethe highest levelof hearing loss. The highest level of hearing loss is equal to 24.0 ± 7.4, which is equivalent to a sound level of 95 dB. When other variables were kept constant, each unit of increase in environmental noise resulted in a 0.46 unit increase in hearing loss.

    Conclusion : The results of this study are in conformity with the relevant standards, particularly ISO 1999. The results show that hearing loss starts from 4000Hz frequency. From the statistics, we can see that the noise parameter has the maximum effect and work experience has the minimum effect on hearing loss.