Noise: An Occupational Hazard

Sound and noise are often used interchangeably. However, they are not the same:

Sound is how we hear the environment around us…
…noise is unwanted sound.

Noise is subjective: playing loud music may be noisy to some, but enjoyable to others. In any case, too much sound can be hazardous and result in hearing loss.

A few indicators of a noisy workplace include:

• Inability to hear the person you are speaking to when you are less than 1 metre apart.
• Ringing in one’s ears at the end of their shift.
• When returning home from work, one must increase the volume on their car radio higher than when they went to work.

While these are good indicators of ‘loudness’, the true noise levels in your workplace can only be determined by a noise assessment conducted by an experienced professional.

Some chemicals (in combination with excessive sound levels) can also cause noise-induced hearing loss. Chemicals which may increase the risk of noise-induced hearing loss are referred to as ototoxins. Ototoxins include certain solvents, metal compounds, nitriles, asphyxiants, and pharmaceutics. It is important to identify the substances used in your workplace and categorize the risks of exposure. This can be done by carrying out a risk assessment.

Under Ontario Regulation 381/15: Noise, the workplace must ensure workers are not exposed to more than 85 decibels (dB) averaged over an 8-hour shift. To determine if the sound level exceeds 85 dB, a noise survey must be carried out. If the workplace is unable to reduce the sound level below 85 dB through engineering controls, then hearing protection is required. In addition to hearing protection, workplaces with exceedances of 85 dB should implement a hearing conservation program.