Noise - Audiometric Tests

What is audiometric testing?

• context Audiometric testing is a type of hearing test. It establishes a baseline measurement of the worker’s hearing and then repeats the testing at regular intervals to determine if there are any changes in the worker’s ability to hear.

Why do audiometric testing?

• context Noise is a serious health hazard. Prolonged exposure to noise in excess of occupational exposure limits can lead to permanent noise-inducted hearing loss, a common occupational disease in Canada.
• context Employers should create and implement a hearing conservation program for workers exposed to noise at the workplace Audiometric testing of a worker’s hearing is important to the success of a hearing conservation program.
• context Audiometric testing helps determine if there are any early indications of noise-induced hearing loss. Because occupational hearing loss happens gradually over time, workers often fail to notice changes in their hearing ability until a relatively large change occurs. By comparing audiometric tests from past years, early changes can be detected and appropriate protective measures can be implemented to prevent further damage. In addition, overall results can be compared from year to year to identify trends within occupations or between different departments at the workplace.

What can workers expect during the test?

• context During an audiometric test, a worker is seated in a sound-treated booth or other appropriate room and a set of headphones is placed over the ears (or inserts placed into the ears). When the worker is ready, the audiometric technician sends a series of tones through the earphones to one ear, and then the other. The worker signals as each tone is heard. The worker’s thresholds are recorded for each ear either on a graph, called an audiogram, or numerically on a chart.
• context The audiogram shows how loud a tone must be to be barely heard by the worker, at a number of different pitches or frequencies. In the early stages of noise-induced hearing loss, the audiogram will show some hearing loss for high-pitched sounds. As hearing loss advances, the audiogram shows a hearing loss for many pitches. Workers with advanced hearing loss will notice the sounds of speech and surrounding sounds becoming muffled.
• context As part of the audiometric test, workers should expect to be counselled about the necessity, use, maintenance, and replacement of hearing protection.
• context An explanation of the test results should be provided to the worker. Workers should also be provided with a copy of their test results.
• context The test results will typically be classified as normal or abnormal. If a worker's test result is found to be normal, no further testing is required until the next scheduled test.
• context If a worker's test result is found to be abnormal, the audiometric technician may ask the worker for additional medical history, and advise the worker to follow up with an appropriate medical professional for more in-depth testing.

Who does the audiometric testing?

• context The employer is responsible for making sure that audiometric tests are conducted by an audiologist or a person who is certified and competent to conduct audiometric testing.

Who should be included in audiometric testing?

• context Workers who may be exposed to excessive levels of noise at the workplace should be included in audiometric testing. Generally speaking, audiometric testing is recommended when a worker is exposed to noise levels greater than 85 dBA (a full shift averaged exposure). However, requirements may vary depending on the legislative requirements in your jurisdiction.
• context Also consider including workers who are exposed to ototoxicants in the workplace. Ototoxicants are chemicals that may affect hearing alone or in combination with noise exposure.

Where do you find audiometric testing requirements in Canadian legislation?

The following are references to the federal, provincial, and territorial legislation where you will find the audiometric testing requirements from the different jurisdictions in Canada. Since legislation is amended from time to time, the jurisdiction should be contacted for the most current information. Where specific requirements are not listed for audiometric testing, please consult with the jurisdiction as it may be covered by other medical surveillance requirements or employer duties. Canada --- British Columbia Occupational Health and Safety Regulation Part 7 Section 7.8 and 7.9 Alberta Occupational Health and Safety Code Sections 223 and 224 Saskatchewan The Occupational Health and Safety Regulations, 2022 Part VIII Section 8-5 Manitoba Workplace Safety and Health Regulation Part 12 Section 12.4, 12.5 and 12.6 Ontario --- Quebec Regulation respecting occupational health and safety Division XV Section 136 New Brunswick Underground Mine Regulation Part III Section 12 Nova Scotia --- Prince Edward Island General Regulations Part 8 Section 8.9 and 8.10 Newfoundland and Labrador Occupational Health and Safety Regulations Part VI Section 68 Northwest Territories Occupational Health and Safety Regulations Part 8 Section 116 and 117 Nunavut Occupational Health and Safety Regulations Part 8 Section 116 and 117 Yukon Territories Occupational Health Regulations Section 6