Document Type : Research articles


1 - PhD Student of Biostatistics, Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

2 Assistant Professor of Biostatistics, Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.


Background: There have been a limited number of studies on the relationships between time and occupational and demographical variables with the mean changes of low-frequency hearing (LFH) and high-frequency hearing (HFH).
Objectives: This study investigated the rate of occupational noise-induced hearing loss (NIHL) due to working in the steel industry and associated effective factors.
Materials and Methods: This historical cohort study was conducted within 2000 to 2010. Two LFH and HFH definitions of NIHL were used in this study. The average changes of LFH and HFL were considered the response variables. In addition, time and occupational (i.e., shift work and work experience) and demographic (i.e., age and educational level) variables were regarded as the independent variables. For data analysis, Bayesian multivariate multilevel modeling using skew distribution and OpenBUGS (version 3.2.2) and R (version 2.13.2) software were used in this study.
Results: The present study was performed on 1,959 male workers with a mean age of 36.64±3.92 years. Among these subjects, 913 (46.6%), 134 (6.8%), and 912 (46.6%) participants were day workers, weekly-rotating shift workers, and routinely-rotating shift workers, respectively. The obtained results showed that age, work experience, educational level, and shift work had significant relationships with the changes of LFH and HFH.
Conclusions: Overall, the findings of this 10-year historical cohort study demonstrated a relationship between time and demographic and occupational variables with the changes of LFH and HFL. Therefore, it is recommended to design preventive measures to reduce the deleterious effects of such variables on LFH and HFL.


  1. Mirza R, Kirchner DB, Dobie RA, Crawford J. occupational noise-induced hearing loss. Occupational Environ Med. 2018;60(9):e498-501. doi: 10.1097/JOM.0000000000001423. [PubMed: 30095587].
  2. Solanki JD, Mehta HB, Shah CJ, Gokhale PA. A study of effect of shift work, sex, and smoking on development of onihl in plastic weavers. Indian J Otol. 2013;19(1):1. doi: 10.4103/0971-7749.108148.
  3. Chou YF, Lai JS, Kuo HW. Effects of shift work on noise-induced hearing loss. Noise Health. 2009;11(45):185-8. doi: 10.4103/1463-1741.56210.
  4. Kim JS. Prevalence and factors associated with hearing loss and hearing aid use in korean elders. Iran J Public Health. 2015;44(3):308-17. [PubMed: 25905073].
  5. Amjad-Sardrudi H, Dormohammadi A, Golmohammadi R, Poorolajal J. Effect of noise exposure on occupational injuries: a cross-sectional study. J Res Health Sci.  2012;12(2):101-4. [PubMed: 23241520].
  6. Eggermont JJ. Effects of long-term non-traumatic noise exposure on the adult central auditory system. hearing problems without hearing loss. Hear Res. 2017;352:12-22. doi: 10.1016/j.heares.2016.10.015 . [PubMed: 27793584].
  7. Jiang W, Zhao F, Guderley N, Manchaiah V. Daily music exposure dose and hearing problems using personal listening devices in adolescents and young adults: a systematic review. Int J Audiol. 2016;55(4):197-205. doi: 10.3109/14992027.2015.1122237. [PubMed: 26768911].
  8. Kempen EV, Casas M, Pershagen G, Foraster M. WHO environmental noise guidelines for the european region: a systematic review on environmental noise and cardiovascular and metabolic effects: a summary. Int J Environ Res Public Health. 2018;15(2):379. doi: 10.3390/ijerph15020379. [PubMed: 29470452].
  9. Neghab M, Maddahi M, Rajaeefard A. Hearing impairment and hypertension associated with long term occupational exposure to noise. Iran Red Crescent Med J. 2009;11(2):160-5.
  10. Halvani GH, Zare M, Barkhourdari A. Noise induced hearing loss among textile workers of Taban factories in Yazd. J Birjand Univ Med Sci. 2009;15(4):69-74.
  11. Nyarubeli IP, Tungu AM, Moen BE, Bratveit M. Prevalence of noise-induced hearing loss among Tanzanian iron and steel workers: a cross-sectional study. Int J Environ Res Public Health. 2019;16(8):1367. doi: 10.3390/ijerph16081367. [PubMed: 30995750].
  12. Singh LP, Bhardwaj A, Kumar DK. Prevalence of permanent hearing threshold shift among workers of indian iron and steel small and medium enterprises: a study. Noise Health. 2012;14(58):119-28. doi: 10.4103/1463-1741.97256. [PubMed: 22718110].
  13. Phillips A, Cooney R, Harris Z, Myrtil D, Hodgson M. Noise and occupational medicine: common practice problems. J Occup Environ Med. 2019;61(12):1019-29. doi: 10.10 97/JOM.0000000000001728. [PubMed: 31592942].
  14. Rogha M, Amiridavan M, Abtahi SH, Sonbolestan SM, Abtahi SM. Early detection of noise induced hearing loss by extended high frequency audiometery. J Isfahan Med Sch. 2007;25(85):16-22.
  15. Rencher AC. Methods of multivariate analysis. 2nd ed. New Jersey: John Wiley & Sons; 2003.
  16. Gholami-Fesharaki M, Kazemnejad A, Zayeri F, Sanati J, Akbari H. A retrospective cohort study on factors associated blood pressure using multilevel modeling. ARYA Atheroscler. 2013;9(5):293-9. [PubMed: 24302938].
  17. Gholami-Fesharaki M, Kazemnejad A, Zayeri F, Sanati J, Akbari H. Historical cohort study on the factors affecting blood pressure in workers of polyacryl iran corporation using bayesian multilevel modeling with skew t distribution. Iran Red Crescent Med J. 2013;15(5):418-23. doi: 10.5812/ircmj.10930. [PubMed: 24349731].
  18. Gholami Fesharaki M, Kazemnejad A, Zayeri F, Rowzati M, Akbari H. Historical cohort study of shift work and blood pressure. Occup Med (Lond). 2014;64(2):109-12. doi: 10.1093/occmed/kqt156. [PubMed: 24526704].
  19. Rubak T, Kock SA, Koefoed-Nielsen B, Bonde JP, Kolstad HA. The risk of noise-induced hearing loss in the danish workforce. Noise Health. 2006;8(31):80-7. doi: 10.4103/1463-1741.33538. [PubMed: 17687183].
  20. Voaklander DC, Franklin RC, Challinor K, Depczynski J, Fragar LJ. Hearing screening program impact on noise reduction strategies. J Agric Saf Health. 2009;15(2):119-27. doi: 10.13031/20 13.26799. [PubMed: 19496341].
  21. Lusk SL. Preventing noise-induced hearing loss. Nurs Clin North Am. 2002;37(2):257-62. doi: 10.1016/s0029-6465(01)00005- 6. [PubMed: 12389266].
  22. Wang D, Zhou Y, Ma J, Xiao L, Cao L, Zhou M, et al. Association between shift work and hearing loss: the Dongfeng-Tongji cohort study. Hear Res. 2019;384:107827. doi: 10.1016/j.heares.2019.107827 . [PubMed: 31683075].
  23. Chou YF, Lai JS, Kuo HW. Effects of shift work on noise-induced hearing loss. Noise Health. 2009;11(45):185-8. doi: 10.4103/1463-1741.56210.
  24. Holzmüller M, Seibt A, Jakubowski A, Friedrichsen G. Studies on the combined effects of shift work and noise on permanent hearing loss. Z Gesamte Hyg. 1990;36(9):501-2. [PubMed: 2238742].
  25. Golmohammadi R, Darvishi E. The combined effects of occupational exposure to noise and other risk factors - a systematic review. Noise Health. 2019;21(101):125-41. doi: 10.4103/nah.NAH_4_18. [PubMed: 32719300].
  26. Zare S, Nassiri P, Monazzam MR, Pourbakht A, Azam K, Golmohammadi T. Evaluation of distortion product otoacoustic emissions (dpoaes) among workers at an industrial company exposed to different industrial noise levels in 2014. Electron Physician. 2015;7(3):1126-34. doi: 10.14661/2015.1126-1134. [PubMed: 26388979].
  27. Farrow A, Reynolds F. Health and safety of the older worker. Occup Med (Lond). 2012;62(1):4-11. doi: 10.1093/occmed/kqr148. [PubMed: 22201131].
  28. Li JH, Tao ZM, Ruan YM, Huang LL, Duan CW, Wang Z. Analysis of factors affecting the noise-induced high frequency hearing loss of male workers in a vehicle manufacturing enterprise. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2019;37(10):760-4. doi: 10.3760/cma.j.issn.1001-93 91.2019.10.009. [PubMed: 31726507].
  29. Irion H. Effect of noise and other factors damaging to hearing on hearing loss. Laryngol Rhinol Otol (Stuttg). 1984;63(2):71-8. [PubMed: 6700339].
  30. Corrêa Filho HR, Costa LS, Hoehne EL, Pérez MA, Nascimento LC, de Moura EC. Noise-induced hearing loss and high blood pressure among city bus drivers. Rev Saude Publica. 2002;36(6):693-701. doi: 10.1 590/s0034-89102002000700006. [PubMed: 12488935].