It is more effective to reduce the noise levels in the workplace than to rely on hearing protection to protect workers. If a noise exposure assessment indicates that workers are exposed to noise levels above 85 dBA (Lex), employers must attempt to use sound control measures to reduce the noise exposures to 85 dBA (Lex) or less. Sound control measures are engineering or administrative controls that eliminate, control or reduce noise exposure, including:
• replacing, changing or eliminating noisy equipment
• distancing workers from sound sources
• enclosing noisy processes or machines
• changing buildings or structures (e.g., installing sound dampening walls and barriers)
• administrative controls such as limiting the length of time a worker is exposed to noise or alternating workers
doing noisy jobs
TRAINING ON NOISE-INDUCED HEARING LOSS
Effective training will provide workers with appropriate knowledge about the effects of high noise exposure levels. All workers should “know their noise” exposure level at work: knowing your dBA (Lex) exposure level is the first step in hearing conservation. The term dBA (Lex) describes a worker’s total sound exposure over an entire work shift. This exposure value is determined using a noise dosimeter (see pages 7-8 of this guide for more on noise exposure assessments).
Training is required when exposure to sound levels is more than 80 dBA (Lex) to make sure workers are aware of noise hazards. Be sure to discuss with workers the ftting, care and use of the hearing protection provided to them. Workers exposed to noise exposure levels of 85 dBA (Lex) or higher need further education about the limitations of hearing protection devices and instruction on inserting the devices correctly.
HEARING PROTECTION DEVICES
Employers must provide hearing protection on request by workers exposed to noise levels between 80 dBA (Lex) to 85 dBA (Lex). Hearing protection devices must always meet the requirements of CSA Standard Z94.2-14 – Hearing protection devices – Performance, selection, care, and use, and must be used when noise exposure levels are at 85 dBA (Lex) or higher. Hearing protection is mandatory when noise is over 85 dBA (Lex).
There are two types of hearing protection devices available:
• earmuffs consisting of a headband and ear cup with a soft outer ring or cushion ftting tightly against the ear or
sides of the head around the ear
• earplugs worn in the external ear canal or in the entrance to the external ear canal.
The type of hearing protection selected depends on the noise exposure levels. You want the workers’ noise exposure reduced to below 85 dBA; however, you don’t want it reduced too much or workers can be overprotected and not able to hear other safety warnings in the workplace, such as forklift horns.