Occupational Noise Induced Hearing Loss Among Grinding Mill Workers in Chennai

IJEP 44(2): 156-160 : Vol. 44 Issue. 2 (February 2024)

Sanjanaa A., Deekshitha A.S. and Daisy Edwin*

Ramachandra Medical College, Sri Ramachandra Institute of Higher Education and Research, Chennai – 600 116, Tamil Nadu, India


Occupational noise induced hearing loss (NIHL) is a permanent sensorineural hearing loss caused by loud noise. Prevention efforts in developing countries are not well structured or strengthened. This comparative cross-sectional study aims to investigate the effects of occupational noise exposure and the prevalence of hearing loss in both a high-risk worker group and a control group using smartphone-based hearing tests. This study included 45 grinding mill workers who were exposed to high levels of machinery noise in the grinding mills and 32 controls from the general population. The noise exposure level of the grinding mills was investigated using a sound level meter (SLM), workers’ risk perceptions and the effects of noise on hearing health were investigated using interview-administered questionnaires and workers’ hearing levels were determined using smartphone Hearing TestTM software (e-audiologia.pl). The grinding mill workers’ noise exposure exceeded the permissible limit set by the Occupational Safety and Health Act (OSHA), the National Institute for Occupational Safety and Health (NIOSH) and the World Health Organization (WHO). Noise-related auditory health effects (tinnitus, hearing loss complaint and speech intelligibility) and non-auditory health effects (blood pressure, headache and sleep disturbances) were found to be higher in the workers when compared to the control group. When compared to the control group, the hearing test result showed a dip at 4 kHz in grinding mill workers. The participants’ auditory thresholds were significantly influenced by the time of exposure and sound level, resulting in noise induced hearing loss among grinding mill workers. The findings may assist us develop better hearing protection guidelines and aids for workers in rice and flour mills.


Sound level, Hearing threshold, Non-auditory effects, Hearing loss


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