An all-too common scenario: A group of workers in a maintenance workshop surrounded by noisy machinery. To communicate with their work buddies, they lift up their earmuffs to try to hear what they are saying, and then quickly put them back on. Well it was only for a few minutes, so surely that’s OK right?
The exposure standard for noise is 85dB(A). That standard was designed to protect against developing noise induced hearing loss for nearly all (not all!) workers. If you are in a noisy workshop, where noise is present at say 110 dB(A), then it will only take around 2 minutes to exceed that standard…which is probably less than the time they took the earmuffs off to talk to their buddy… So no, it’s not OK!
So what can you do? Well as a start if you are in a noisy workplace, you should have a competent occupational hygienist perform an occupational noise survey. The hygienist will then be able to guide you in recommending measures that would reduce the source of the noise (so maybe you don’t need earmuffs at all!), or noise-attenuating measures to at least reduce the noise. The use of hearing protection is always the last resort…but if you do need to wear them, keep these following points in mind:
- The use of hearing protection can actually improve speech perception in noisy environments. Going without protection in order to communicate should never be the approach as the excessive noise will overload the ears and the unprotected noise exposure is likely to result in noise induced hearing loss which will in turn cause greater difficulty communicating in the future.
- You can use several tactics to improve speech communication. These include:
- Training workers to speak loudly and distinctly. This is to overcome the occlusion effect where workers tend to speak quickly in noise.
- Using visual clues for speech whenever possible, including hand gestures, and watching the speakers face directly.
- Developing key works or phrases specific and meaningful to the work environment such as creating shorter terms for repetitive processes.
- Providing workers time to adjust. The brain has the ability to learn to fill in the gaps for what it doesn’t hear by integrating all the information so that speech discrimination will improve with experience. It is for this reason that new and experienced workers should be encouraged to work together.
- Utilising specialty hearing protectors that amplify speech whilst limiting the output to a safe level below 85 dB(A).
- Developing individual plans for hearing-impaired workers who may need specialized hearing protection.
Another key piece of information is that different types of hearing protection reduce certain frequencies more than others, including attenuating high frequencies such as speech more than low frequencies such as background noise. To figure out which one is best for your workers at your workplace, you will need an Occupational Hygienist.
Is that all? Not even close. When PPE is used to control exposure, it’s not as simple as just handing a few workers a bunch of earmuffs. The use of PPE actually involves a large administrative burden as you need to provide training to the workforce (including written and verbal instructions), audiometric (medical) assessments, provide signage/warning notices where they are needed, provide effective supervision, and the list goes on and on. This is a good resource to use as a start, and you could consider the use of electronic-amplified ear-muffs which can also transmit the 2-way radio through the earmuffs…slightly more pricey…but can you put a price on hearing loss?
Where do I go for help? Well ask your friendly occupational hygienist!