Audiometric testing in New Brunswick workplaces

Workers exposed to excessive noise levels need to have audiometric testing. Employers must identify these workers through a noise assessment, including both seasonal and temporary workers who are exposed.

Any worker who is or may be exposed to excess noise must comply with the hearing conservation code of practice including having audiometric testing.

When a worker is or may be exposed to excessive noise, the worker must have a baseline audiogram as soon as circumstances permit, but no later than six months after employment begins. This requirement also applies if there is a change in a worker’s activities or duties that results in noise exposure. Additional tests are required at least once every 24 months after the baseline test if the worker continues to be employed with the employer. The bi-annual test results can then be compared with the baseline audiogram to check for changes in hearing.

Baseline test: To avoid a temporary threshold shift during testing, the ideal time to perform a baseline hearing test is before a worker begins their shift or after 14 hours of non-exposure to excessive noise. If this is not possible, workers may be tested during their work shift, provided the worker wears hearing protection during their shift to reduce their exposure to noise.

Bi-annual tests: Bi-annual tests should be scheduled well into the work shift (ideally one-third of the way into the shift), if possible, so that temporary changes in hearing can be noted. This allows for comparison with baseline results to monitor changes in hearing sensitivity, identify temporary hearing loss before it becomes permanent, and the implementation of corrective control measures.

Yes, workers can be tested on the work site by an audiologist or a certified administrator (see section, Who does the audiometric testing?), provided the testing area does not exceed the maximum permissible ambient noise levels that could mask the tones used during the test. Employers who are unsure about the level of permissible noise should consult with a competent person who can assess the room’s suitability, using the CSA Standard Z107.6:16 (R2020), “Audiometric testing for use in hearing loss prevention” or a standard offering equivalent or better protection.

Workers can also be tested at an off-site or a mobile-unit testing centre, which typically have sound-treated booths that better control ambient noise.

During an audiometric test, a worker sits in the sound-treated booth or appropriate room with headphones or ear inserts. The audiometric technician sends a series of tones to each ear and the worker signals when a tone is heard. These responses are recorded on an audiogram, which shows how loud a tone must be to be barely heard at various frequencies.

Early stages of noise-induced hearing loss appear as a loss of hearing for high-pitched sounds. As hearing loss advances, the audiogram will show hearing loss for many pitches. Workers with advanced hearing loss may notice speech and surrounding sounds becoming muffled.

As part of the test, workers should also receive counseling on the necessity, use, maintenance, and replacement of hearing protection.

The employer is responsible for ensuring that tests are conducted by

• an audiologist who is registered as a member of the New Brunswick Association of Speech-Language Pathologists and Audiologists (NBASLPA),
• or a person who successfully completed a training course referred to in clause 6 of CSA Standard Z107.6:16 (R2020).

When hiring a service provider to conduct audiometric testing, the above requirements must be met. The New Brunswick Association of Speech-Language Pathologists maintains a searchable directory to assist with finding a service provider.

The employer must ensure that a competent audiometric technician is selected to provide the following services:

• Performing the audiometric test
• Collecting medical history from the worker, where appropriate
• Interpreting the test results
• Counseling the workers on the state of their hearing, comparing it with previous tests whenever possible
• Maintaining records
• Advising workers on appropriate hearing protection.

The employer must also ensure that hearing protection selected for use meets the requirements of CSA standard Z94.2-14 (R2019) Hearing protection devices — Performance, selection, care and use.

Audiometric testing must be conducted using an audiometer that meets the specifications outlined in the CSA standard Z107.6:16 (R2020), Audiometric Testing for Use in Hearing Loss Prevention Programs or a standard offering equivalent or better protection. Calibration of audiometers and related equipment is critical for reliable test results and must be performed bi-annually, following the CSA Standard Z107.6:16 (R2020) “Audiometric Testing for Use in Hearing Loss Prevention Programs”.

The results will typically be classified as normal or abnormal. If a worker’s test result is normal, no further testing is required until the next bi-annual test. If the result is abnormal, the audiometric technician may request additional medical history and advise the worker to follow up with an appropriate medical professional for further testing.

Employers are required to keep records of the:

(i) initial and subsequent hearing tests for each employee and the results must be kept:

• as long as the worker is employed with the employer;
• confidential,

(ii) instruction and training provided on the hazards of noise exposure,

(iii) correct use of control measures and hearing protective equipment and

(iv) noise level measurements taken as required in section 29 of Regulation 91-191.

If you would like more information, you can contact WorkSafeNB at 1 800 999-9775 (option 2) or by emailing prevention@ws-ts.nb.ca. Additional health and safety resources can be found at:

• WorkSafeNB
• WorkSafeNB – OHS Guide: Noise
• Canadian Centre for Occupational Health and Safety
• Canadian Standards Association