Hard of hearing people who work in an environment in which noise exposure is overly intense, might miss important danger signals due to their hearing. A Canadian study reveals that hearing loss, combined with noise in the workplace, increases the risk of serious work injury. Complementing sound signals for safety with visual signals could be the answer.
Hearing loss and work injury
Records of 46,550 male workers were used by the researchers to compare the workers’ levels of hearing and their exposure to loud noises in the work place. During 5 years, a total of 1,670 subjects had been hospitalised for work-related injuries.
The researchers found that for every dB of hearing loss, the risk of hospitalisation due to work-related injuries increased by 1%.
Furthermore, when working in an environment where noise exposure reaches above 100dB, the risk of serious work-related injury increases by 2.4 times compared to workers not exposed to loud noises.
Based on the study, the researchers estimate that the combination of severe hearing loss and working in a noise exposed environment of 100dB increased the risk of injury by 3.6 times compared to workers with neither factor.
Signals of safety
While the usual reason to control noise in the workplace is to protect the hearing of the workers, the current study suggests another major reason, namely workplace safety.
Workers with hearing problems might miss important sound signals while working. To improve the level of safety, researchers recommend combining sound signals for safety with other types of signals that do not rely as much on hearing e.g. visual signals.
Another recommendation is to use special types of hearing protection or assistive devices that help a hard of hearing worker to function well in a noisy environment.
About the study
The study was conducted by researchers from National Public Health Institute of Quebec in Quebec City, Canada and published in the Journal Injury Prevention.
While the study focused on noise exposure of 100dB in the workplace, future research is needed to assess the risk of work-related injury among workers with hearing loss at lower levels of noise, e.g. between 80dB and 90dB.