Noise is a serious problem in the workplace. Over time excessive noise can lead to permanent hearing loss. It is important for the worker to understand noise, and how to prevent hearing loss. Damage to hearing will not return over time.
How is noise measured?
- Noise is measured in units called decibels dB. This is the intensity or loudness of the noise
- Frequency of noise will affect how the noise effects hearing. “A” weighted filter refers to noise that is hazardous to the human ear
- Duration of noise is usually described as a time weighted average. The average noise exposure over an 8 hour period
What is too much noise?
- Exposure to noise levels greater than 85 dBA over an 8 hour period
- Exposure to impact noises above 140 dBC must not be exceeded
- A regular conversation is between 50 and 70 dBA.
- Guideline: If you have to raise your voice to carry out a conversation the noise level is above 85 dBA
How to protect against hearing loss?
- The best way to prevent hearing loss is to remove the source of the noise or block the noise before it reaches the worker
- The last line of defense is PPE. Earmuffs and earplugs are the most common type
- Each style of PPE has a noise reduction rating. Ensure the noise reduction is appropriate for the environment
- A noise reduction rating of 32 dBA does not reduce the noise exposure by 32 dBA
- Example: 98 dBA environment, earplugs with a noise reduction rating of 32 dBA
- Estimated noise exposure = 98-[(32)(0.5)-3] = 85 dBA
- Example: 98 dBA environment, earplugs with a noise reduction rating of 32 dBA