Health & Safety View

Hearing conservation

Noise at the workplace is one of the most common occupational hazards. Noise levels can affect an individual’s productivity, concentration, and health. To prevent the adverse outcomes of noise exposure, both noise levels and the duration of exposure should be reduced. Noise is unwanted or disruptive sound.

How does noise impact hearing?

Sound is produced when objects vibrate resulting in air pressure changes which travels as waves in the air. Once the waves reach our ears, parts inside the ear can sense the change in pressure. These parts amplify the vibrations and cause tiny hairs in the inner ear to bend. Bending those hairs creates nerve impulses that the brain perceives as sound.

At acceptable noise levels, these hairs easily return to their original position. As noise intensity, frequency and/or duration increases, the vibrations become too strong or last too long and the hairs can be permanently damaged causing hearing loss.

Safe noise levels in the workplace

Sounds may be harmful if one of the following is noted:

You have trouble talking or hearing others talk. As a guideline, if you need to shout to be heard when standing within 1 meter of another person at work then the sound is likely excessive.
The sound makes your ears hurt.
Your ears are ringing and/or other sounds seem muffled after leaving a space.

WorkSafeBC has strict limits for the levels of sound permissible in the workplace. WorkSafeBC Occupational Health and Safety Regulations Section 7.2 sets the following exposure limits:

85 dBA daily noise exposure level (A-weighted filter, averaged over an 8-hour period)
140 dBC peak sound level (maximum intensity on a C-weighted filter)

Alternatively, as a preliminary measure, smartphone applications can be used to determine whether further sound level testing is required. However, the microphone in your smartphone will vary in accuracy and cannot be calibrated properly. It is best to assume that the sound measurement has a margin of error +/- 10db.

Measuring noise levels in the workplace

To obtain accurate results, workplace noise is measured using a noise dosimeter or sound level meter. If you are concerned that noise in your workplace exceeds 85 dBA or 140 dBC, contact UBC Research Safety to arrange an on-site noise assessment. This assessment will determine if additional noise control measures or hearing tests are required for your area.

Reduce noise hazards

Under the UBC Hearing Conservation Program, the hierarchy of controls must be implemented when controlling noise exposure. Start by speaking to your supervisor to determine what is possible to implement in your workplace.

Control Type	Examples
Elimination/Substitution	Purchase a quieter machine or piece of equipment Find a workplace away from the noise
Engineering Controls	Enclose the noise source* Enclose workers from the noise using isolation booths* Acoustically treat the room* Maintain/lubricate moving parts *Approval requirements from professional engineers must be taken into consideration
Administrative Controls	Reduce work hours to limit exposure time Schedule work at a distance Develop and implement hearing conservation program Post warning signs Participate in the annual hearing testing program
Personal Protective Equipment (PPE)	Providing hearing protection devices such as earplugs or earmuffs and ensuring their appropriate use

Hearing tests

All workers who are exposed to noise that exceeds exposure limits (85 dBA daily or 140 dBC peak sound levels) must receive a hearing test no later than 6 months after starting work and annually thereafter. Hearing testing can be scheduled by contacting UBC Research Safety.

What if noise is irritating but below exposure limits?

Noise levels below 85 dBA is called nuisance noise. Nuisance noise is not likely to damage hearing but can have an adverse effects that cause stress, and impact employee performance.

The cause of nuisance noise is wide ranging and can be difficult to control. Due to its negative impacts, nuisance noise should be managed locally to reduce it as much as possible.