Noise Hazard and Hearing Loss Among Mold Manufacturing Industry in Penang

Ng, Yee Guan1; Subash Saralan2

Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia,43400 Serdang, Selangor, Malaysia1,2

Page 1 – 12  |   Vol. 7 No. 2 2022   |    Available online on 30 Dec 2022


Abstract: Introduction: Exposure to occupational noise from process of mold manufacturing may cause workers experiencing hearing disorder. Present study shall focus on association of employee sociodemographic, occupational information and social lifestyle against prevalence of hearing disorder among the mold manufacturing workers. 

Method: A cross sectional study were conducted among 40 workers from a mold manufacturing company. Personal noise monitoring had also been carried out for workers to determine noise exposure level LEX, LMAX and LPEAK during their 8 hours work shift whereas the hearing threshold was obtained from recent annual audiometric test record carried out by DOSH approved mobile audiometric centre. Statistical analysis using Pearson correlation and Chi-Square has been carried out to test the relationship between the variables (IV and DV).

Results: It was found that primarily, the age of mold manufacturing workers were significantly correlated with LHL [rs = – 0.311, P = 0.025], RHL [rs = – 0.289 P=0.035], LSTS [rs = – 0.349, P = 0.014] and RSTS [rs = – 0.349, P = 0.014]. LEX was correlated with RHL only [rs = – 0.27, P = 0.046]. Age was also correlated with overall HD [rs = – 0.351, P = 0.013]. Despite provided with PHP, recommended based on the calculation of the noise attenuation below NEL, hearing disorder were still observed among the employees. Surprisingly, the trend of presbycusis were observed among workers below the age of 30 years old where in some cases they were non-occupationally related.

Conclusion: It is not a surprise that age and Lex of the mold manufacturing workers were associated with prevalence of hearing disorder among mold manufacturing workers. However, further research or investigation should be carried out to consider non-occupational factors which may affect the worker’s hearing threshold.


Mold manufacturing, noise exposure, hearing loss, hearing disorder

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Human Factors & Ergonomics Journal (HFEJ), eISSN: 2590-3705  is the official Journal of Human Factors and Ergonomics Society Malaysia.  The journal is published on a biannual basis. HFEJ aims to address current research in the field of Ergonomics in addition to the broad coverage of cognitive ergonomics, user experience, physical ergonomics and others such as transportation, industrial design and industrial engineering. HFEJ is a member of, and subscribes to the principles of the COPE (Committee on Publication Ethics), as such we only accept original work.