A guide for any Industry. How to Choose the Right Hearing Protection – (part 1)
This is part 1 of a series on how to choose the right hearing protection as part of the Personal Protective Equipment (PPE) and what things to consider. In this series we will help you to make informed choices and save money while putting safety of hearing at the forefront.
We will go into several different aspects to consider, such as noise levels, cost effectiveness, certification AS/NZS1270, comfort, attenuation, durability, type of noise (frequencies), and more.
Responsibilities and liabilities
Most of you know that under law employers are responsible for providing a range of protection to their staff as part of their PPE. Most of you also know that hearing protection is part of these obligations.
Yet, hearing protection is seldom at the forefront of discussions around PPE. Whereas other injuries are directly visible and noticeable, the damage done to hearing goes mostly unnoticed for years.
There are several types of hearing loss, but as this series focuses on workplaces, we will focus on Noise Induced Hearing Loss (NIHL), the hearing loss caused by being exposed to excessive noise levels. It can be caused by a one-time exposure to an intense “impulse” sound, such as an explosion, or by continuous loud sounds over an extended period of time.
It is a fact that most NIHL is caused in the workplace. NIHL is the only type of hearing loss that is completely preventable if and when you take the right measures and use the right hearing protection.
In order to limit hearing damage, the employer is responsible for taking all necessary measures available to reduce noise but also for providing proper hearing protectors, and t also to oversee the (proper) use of these. Choosing proper hearing protectors is what we are going to focus on.
To choose the correct hearing protection we need to start looking at three things first: noise levels, noise frequencies and attenuation.
Noise Levels – how loud is that sound?
1. Part of the solution to the NIHL is knowing that noise that exceeds 85 decibels (A-weighted) or dBA can damage hearing. At an average of 85db over an 8-hour workday people are generally safe from hearing damage. However, the higher the noise level or the longer the exposure, the more chance of hearing damage. A sudden intense “impulse” noise can also change these numbers.
Every increment of 3db above 85 however, halves the safe exposure time. It is important to realise that a 6db increase above 85db leads to 2-hour safe exposure time only (half of half) and so on. It is not a linear scale but an exponential scale.
As a matter of comparison, firearms work around 140db, a factory or chainsaw around 100db, a jackhammer around 130db. Without proper protection working in a factory (as in our example) would only be safe for 15 minutes per day. All noise that exceeds 85db after those 15 minutes, is damaging.
For those interested, try the Safe Exposure Time Calculator
Frequency Levels – What type of noise? Highs and Lows
2. The second important part about noise is that all noise is different, has different frequencies. A train engine produces mostly low frequency noises, whereas a siren produces mostly high frequency noises.
There are hearing protectors with different protective abilities, in other words that protect at different frequency levels. A protector that attenuates (protects) against high frequency noises mostly, will not be as suitable for people working in a place where the damaging noise levels are mostly in the lower frequencies. It is important to choose the right product for the kind of noise you are exposed to.
Attenuation – How much reduction are we going to apply?
3. We know noise levels and frequencies, the last important part is attenuation. How much noise is going to be filtered? Is a Class 5 needed or is it safer to use a Class 3?
Important is to acknowledge that people will still need to hear and to stay aware of surroundings, not being isolated, hear the radio, make phone calls, talk to others, be warned etc. without taking off the hearing protection. Part of the day-to-day safety is spatial awareness. Too much attenuation and staff will be reluctant to wear them or are enticed to take them out to listen or talk to someone while noise levels are still excessive. Obviously, this will still cause damage to their hearing.
To have the best of both worlds, being safe and protected, choosing an attenuation level that lowers the noise to or just below 85 db is preferable. These levels are safe while people can still communicate.
Conclusion – part 1
Hearing protection is very specific to the industry, business, department, position and/or person involved.
Important to recognize are the noise levels, the frequency of the damaging noise, and the attenuation levels.
One size doesn’t fit when it comes to hearing protection. It is a waste of time, effort and money not doing it right.
Next in this series: Cost Effectiveness and Durability
If you would like more information in the meantime, please contact us at any stage.