At What Decibel Level Is Hearing Protection Required?

Noise-induced hearing loss can happen gradually, which makes workplace noise easy to underestimate. A worker may finish a shift without noticing an obvious change in hearing while repeated exposure is still causing damage over time.

In Alberta, employers are responsible for controlling workplace noise and ensuring workers are not exposed above the occupational limits established in the Occupational Health and Safety Code. The key number is 85 dBA Lex, which represents a worker’s total daily noise exposure adjusted to the equivalent of an eight-hour workday.

But the answer to “at what decibel level is hearing protection required?” is not quite as simple as saying 85 dBA. How loud the noise is and how long a worker is exposed to it both matter.

The Workplace Noise Exposure Limit in Alberta

Under Alberta’s OHS Code, a worker’s occupational noise exposure cannot exceed 85 dBA Lex or the exposure limits set out in Schedule 3. Employers must also conduct a noise exposure assessment if workers are or may be exposed to more than 82 dBA Lex.

Lex is important because it accounts for exposure over the entire workday. A worker exposed to moderately high noise for eight hours may receive the same overall noise dose as someone exposed to much louder noise for a shorter period.

Alberta uses a 3 dB exchange rate, meaning that every 3 dB increase in noise cuts the permitted exposure time approximately in half.

This is why simply knowing that a machine produces “90 decibels” is not enough. Employers also need to understand how long employees are working around that equipment and what other noise they are exposed to throughout the shift.

How Do You Know if a Workplace Is Too Loud?

Some workplaces are obviously noisy. Construction sites, manufacturing facilities, sawmills, welding shops, airports, oil and gas operations, and other industrial environments can expose workers to significant sound levels.

However, you should not rely on how loud a workplace feels.

If employees are or may be exposed above 82 dBA Lex, Alberta requires a formal noise exposure assessment. This assessment must be completed using appropriate equipment such as a noise dosimeter or sound level meter and interpreted by a competent person.

Noise measurement can identify:

• which areas of the workplace are generating excessive noise;
• how much noise individual workers are exposed to;
• how exposure changes throughout a shift;
• whether existing controls are effective; and
• where additional hearing protection or noise controls may be required.

Proper measurement gives employers real information to work with rather than guessing whether noise levels are acceptable.

What Happens if Employees Are Exposed to Excess Noise?

When a noise exposure assessment confirms excess workplace noise, Alberta employers must implement a noise management program.

That program must address how noise will be measured and controlled, educate workers about the hazards of excessive noise, provide training on hearing protection, establish the selection and use of hearing protection devices, and address audiometric testing requirements. Areas where noise exceeds 85 dBA must also have appropriate warning signs.

Where reasonably practicable, employers should first work to reduce noise at the source. That can include quieter equipment, enclosing noisy machinery, acoustic barriers, equipment maintenance, isolation, or changes to work processes.

Administrative controls can also reduce exposure by changing how long workers spend in noisy environments.

When hearing protection devices are used, Alberta requires them to meet the applicable CSA standard and to be fit tested.

Rocky Mountain Mobile Hearing Testing provides hearing protection fit testing to help employers determine whether the protection employees are wearing is providing an appropriate fit.

What Types of Hearing Protection Can Workers Use?

Hearing protection devices are designed to reduce the amount of harmful noise reaching the ear.

Common options include:

• disposable or reusable earplugs;
• custom hearing protection;
• earmuffs;
• canal caps; and
• specialized or electronic hearing protection.

The right option depends on the work environment, exposure level, worker comfort, communication requirements, and how well the protection actually fits the individual employee.

A hearing protector may have a published noise reduction rating, but that does not automatically mean every worker receives that amount of protection in the real world. Poor insertion, incorrect sizing, interference from other PPE, or simply wearing the wrong device can significantly reduce its effectiveness.

That is one reason hearing protection fit testing is important. It provides a more practical indication of how much protection an individual worker is actually receiving.

Why Is Audiometric Testing Important?

Noise measurement tells you what is happening in the workplace. Audiometric testing tells you what is happening to the worker’s hearing over time.

Under Alberta’s OHS Code, employers must provide audiometric testing for workers who are or may be exposed to excess noise. This includes an initial baseline test, another test within 12 months, and testing at least every second year after that.

Regular audiometric testing allows changes in hearing thresholds to be tracked over time and can help employers evaluate whether their hearing conservation efforts are working.

Rocky Mountain Mobile Hearing Testing provides mobile audiometric testing so employers can test workers directly at the job site with minimal interruption to the workday.

What Are the Signs That Noise May Be Affecting Your Hearing?

Workplace noise should be measured rather than judged by symptoms alone, but there are warning signs that should never be ignored.

Workers may notice:

• ringing or buzzing in the ears;
• temporary muffled hearing after a shift;
• difficulty understanding conversations;
• needing to turn up the television or phone;
• trouble hearing in environments with background noise; or
• needing to shout to communicate with someone nearby.

These signs can indicate that workplace noise exposure needs to be investigated.

Once noise-induced hearing loss occurs, it can be permanent. Prevention, monitoring, and properly fitted protection are therefore much more effective than waiting for noticeable hearing damage to develop.

How Can Employers Reduce Excessive Workplace Noise?

There is no single solution that works for every workplace. Effective hearing conservation usually combines several approaches.

Employers can reduce worker exposure by controlling noise at the source, using quieter machinery, maintaining equipment properly, installing acoustic barriers or enclosures, increasing distance between workers and noisy equipment, and limiting the amount of time employees spend in high-noise areas.

Appropriate hearing protection should then be selected, properly worn, and fit tested as part of the overall program.

Regular noise measurements and audiometric testing can help determine whether those controls continue to work.

For more ideas, read our guide to workplace hearing protection strategies.

Frequently Asked Questions About Hearing Protection Levels

At what decibel level is hearing protection required in Alberta?

Alberta sets a maximum daily occupational exposure of 85 dBA Lex, with additional exposure limits based on the actual sound level and duration. A workplace noise assessment is required when workers are or may be exposed above 82 dBA Lex. Where workers are exposed to excess noise, hearing protection forms part of the required noise management program.

Why does exposure time matter?

Noise risk is based on both intensity and duration. Under Alberta’s 3 dB exchange rate, the allowable exposure time is cut roughly in half every time noise increases by 3 dB. That means 85 dBA is permitted for eight hours, while 88 dBA is limited to four hours and 91 dBA to two hours.

Do hearing protectors need to be fit tested?

Yes. Alberta’s OHS Code requires hearing protection devices used by workers to meet applicable CSA requirements and to be fit tested.

Are earplugs enough for every noisy workplace?

Not necessarily. The appropriate hearing protection depends on the measured exposure, the type of noise, the job being performed, and the fit and performance of the hearing protector. In some environments, additional controls or different forms of hearing protection may be necessary.

Rocky Mountain Mobile Hearing Testing provides mobile audiometric testing, custom hearing protection, hearing protection fit testing, and workplace occupational testing for companies throughout Calgary and Western Canada. If you need help understanding workplace noise exposure or protecting employees from occupational hearing loss, contact our team at (403) 399-4775.