Audiometry testing is required in Alberta when workers will be exposed to detrimental levels of noise. This goes hand-in-hand with providing adequate and appropriate hearing protection. For an employer to determine whether or not they require hearing protection and audiometric testing, they are required to complete a site survey.


This process involves going to each area that has the potential for high levels of noise and testing the decibel level with calibrated and working equipment. It must also be performed by certified technicians who can interpret the results and prepare a report based on the testing performed. But, once this step is completed, how do they determine appropriate hearing protection?



How Did We End Up with Audiometry Testing?


What is an Occupational Exposure Limit?

An occupational exposure limit (OEL) is a limit set by the Alberta or Federal government to determine the acceptable level of exposure for a worker in a typical shift. These OEL’s exist for all sorts of hazardous materials, including chemicals, airborne contaminants, and noise. During the site testing, described above, the ultimate result is a report stating the amount of exposure, measured in decibels, a worker will receive when working in a noisy area. 

Set of molded red ear plugs with a cord

It is then an employer’s responsibility to select and implement hearing protection that lowers their exposure below the OEL. Employer’s typically complete this task by speaking with their safety equipment providers, but how do the providers know how much the noise is reduced?


What is a Noise Reduction Rating?

A noise reduction rating (NRR) is the measure of hearing protection an individual item will offer. It can be a little strange to measure, but essentially, if you halve the NRR you will have the number of decibels it reduces from the total. For example, earplugs typically have an NRR of 30-40 which means the decibels are reduced by 15-20. 


Proper safety equipment and policies must be put in place to reduce the total amount of decibels a worker is subjected to in an 8-hour shift. 


As an example of this, industrial sandblasting equipment typically operates between 100-120 decibels. A sandblaster who will be exposed to this level of noise will be required to wear well-fitted, disposable earplugs, reducing their exposure to roughly 80-100 decibels. As the OEL for noise in Alberta sits at 88 decibels, this is almost sufficient. But then, they must wear insulated blasting hoods to protect their heads and lungs from the sandblasting dust, which carry their own NRR of 30-40. This further reduces their exposure to 60-80 decibels, and they are now no longer exposed to the detrimental effects of noise. 


Audiometry Testing Ensures Protective Equipment Works

So now that we know how employer’s responsibilities to their workers are determined, why do we need audiometric testing? We need it because it establishes a baseline, and tests workers hearing year over year to ensure their hearing does not worsen, which would be a sign their hearing protection is not adequate.


Rocky Mountain Mobile Hearing Testing is your locally owned and operated Calgary business. We are committed to providing mobile hearing testing services and other safety tests, to numerous industries and companies in Western Canada. Our services are part of the WorkSafeBC Provider Network, while our sound booths are approved by the CSA. We offer audiometry testing, mask fit testing, custom earplugs, noise measurements, help with implementing a hearing conservation program, and spirometry testing. If you want to improve your workplace, leave it in the hands of our team. Contact us today on (403) 399-4775.