The Impact of Noise on Hearing Performance among Employees in a Metal Can Manufacturing Factory in Samut Prakan Province, Thailand

Abstract

Objective: To examine the level of hearing performance and the impact of noise on the hearing performance of employees in a metal can manufacturing factory in Samut Prakan Province. Methods: This study employs a cross-sectional descriptive research design involving a sample of 189 employees from a metal can manufacturing factory in Samut Prakan Province. Data were collected through questionnaires, sound level meters, and audiometer. Data analysis was performed using a statistical software package, which included descriptive statistics and inferential statistics such as the Chi-Square test. Results: The majority of employees exhibited abnormal hearing levels, with 62 individuals affected. Among them, 59.7% had impairments in low-frequency hearing, while 40.3% experienced high-frequency hearing impairments. Factors influencing employees' hearing capacity were categorized into two groups: (1) risky behavioral exposure to loud noise in daily life, which significantly affected low-frequency hearing (p-value = 0.022), and (2) work tenure and experience of noise exposure in the workplace, which significantly affected high-frequency hearing (p-value < 0.001 and 0.001, respectively). Conclusion: This study highlights that exposure to industrial noise impacts hearing ability at different frequencies. Specifically, noise from machinery in metal can manufacturing factories predominantly damages high-frequency hearing receptors, an effect that may not be immediately noticeable in daily life. Employees may remain unaware of their hearing impairment unless assessed using specialized equipment. Therefore, employers should implement regular audiometric testing for employees at least once a year, based on their risk level, to monitor and prevent hearing deterioration.