Page 18 - OHS, September 2024

NOISE MONITORING
Noise Monitoring: A Sound Strategy
Effective noise monitoring and control measures in the workplace are crucial to preventing noise-induced hearing loss and ensuring employee safety.
BY TIM TURNEY
The world is getting louder. People cannot escape noise pol- lution in their everyday lives whether from traffic, infra- structure, music or more, but employees can and must be protected from excessive noise in the workplace. Exposure to loud noise kills the nerve endings in ears.
When compounded over a long time, this can result in noise- induced hearing loss (NIHL), a permanent occupational illness that blights at least 10 million people in the U.S., according to the Na- tional Institute on Deafness and Other Communication Disorders.1
Those with affected hearing are more likely to develop demen- tia, suffer from social isolation, have weakened processing abilities and are at a higher risk of physical injury due to a lack of awareness of immediate hazards.
Under OSHA’s Noise Standard, the employer must reduce noise exposure through engineering controls, administrative controls or Hearing Protection Devices (HPDs) to attenuate the occupational noise received by the employee’s ears to within specified levels.2
Terminology
Employees that are subjected to loud, instantaneous noise can suf- fer from immediate noise induced hearing loss that cannot be re- paired. Similarly, lower levels of noise over the course of a working life can also cause similar damage, but due to the lengthy period of time this takes, this can often be ignored.
Workplace noise terminology can be difficult to understand for
those that are not trained, as employers will often work with consul- tants or other experts to ensure compliance. It is just as important for employees to understand how noise is measured and the respective limits placed on noise levels to protect employees in the workplace. To improve employee engagement and awareness in understanding the risks of occupational deafness and other hearing related diseases, a better understanding of this terminology is the best place to start.
Sound is measured in decibels (dB), a logarithmic scale. With NIOSH standards, this means that every three-decibel increase equates to double the amount of sound energy. This doubling of noise energy also equates to a doubling of the risk of hearing dam- age, making relatively small increases in deciBels have a signifi- cant effect on employee health. Sound values will have a dBA unit attached to them, the ‘A’ refers to A-weighted sound levels which closely match the perception of loudness by the human ear.
It depends on the local legislation, but in the United States, there are two different types of “action levels” or values. OSHA imple- mented a permissible exposure limit (PEL) of 90dBA for all workers for an eight-hour day. The National Institute for Occupational Safety and Health (NIOSH) has recommended that all worker exposures to noise should be controlled below a level equivalent to 85 dBA over eight hours to minimize occupational noise-induced hearing loss.
The eight-hour exposure period is referred to as the Time Weight- ed Average (TWA). These exposures are all standardized to an eight- hour working day so that individuals with different exposure times
16 Occupational Health & Safety | SEPTEMBER 2024
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