The team of occupational hygienists at Safe Environments provide occupational noise assessments to measure sound levels and assess exposure, which subsequently allow them to provide control strategies to ensure the risk of noise induced hearing loss is minimised.
NSW WorkCover has identified that industrial deafness accounts for approximately 36% of all occupational injuries. It is both irreversible and preventable. To this end the NSW OH&S regulation requires that appropriate controls measures be in place if people are exposed to an average of 85 dB(A) for 8 hours, with a peak level of 140 dB(C).
An simple walk through noise survey will assist work site managers to identify if their employees are at risk of noise induced hearing loss. If noise levels exceed 80 dBa then a more detailed occupational noise assessment from Safe Environments may be required, and it is recommended that the principles of AS/NZS 1269 occupational noise management be implemented to identify, assess and control the risk of noise induced hearing loss.
This detailed occupational noise assessment involves taking noise level measurements to provide a contour map of excess noise sources and effects of reflecting surfaces and reverberant fields. During an occupational noise assessment, Safe Environments also take further measurements during specific tasks which help them to assess the noise exposure to workers.
Noise measurements are undertaken to AS/NZS 1269.1; the safety standard for measurement and assessment of noise emission and exposure. During the task measurements are taken in near proximity of workers' ears using a Class 1 sound level meter to obtain the average noise exposure. By assessing all tasks normally conducted during the day, the total daily noise exposure can be calculated.
Alternatively, a personal sound exposure meter will integrate and average the noise recorded during the day to provide the total noise exposure to the worker.
The ranking of the activities and noise sources for each exposure group provides a basis to systematically control excessive noise through eliminating certain processes and implementing quiet equipment or hearing protector programs. While not all noise levels can be reduced to acceptable limits, the use of such solutions can make a significant difference.
Baseline noise levels should be conducted prior to starting work on a project, with annual occupational noise assessments made to determine hearing threshold shifts and potential noise induced hearing loss. Auditory assessment should also be conducted at the termination of employment to quantify any change in hearing loss.