01 July 2020
Noise induced hearing loss is irreparable but avoidable, so it is time to start taking hearing protection seriously, says Peter Dumigan.
LONG-TERM damage to your hearing can be caused by the noise from regular daily use of even the most basic hand tools – drills, angle grinders, disc cutters, circular saws, even hammers – if you don’t wear proper ear protection.
The Control of Noise at Work Regulations 2005 are designed to workers on site from the risks caused by noise.
Noise induced hearing loss is the most commonly reported occupational disease with over 800 million people around the world are affected by the condition.
Over 30% of all workers are exposed to hazardous noise levels and one in four manufacturing workers who are exposed to loud noise does not use hearing protectors.
Hearing damage caused by exposure to noise at work is permanent and incurable with research estimating that over 2 million people can be exposed to noise levels that are potentially harmful.
More often than not, hearing loss is gradual as a result of prolonged exposure to noise, but when combined with normal loss of hearing as you age it becomes a rapidly deteriorating condition.
As an added hazard, exposure to unsafe noise levels can also result in tinnitus, a permanent sensation of background ringing or buzzing your ears. But in the most serious of cases, immediate damage to your hearing can also be caused by sudden loud noises.
As far as the health and safety regulations are concerned, the noise threshold for providing hearing protection is now a daily exposure of 85 decibels. More importantly, the level at which employers must assess the risk to workers' health and provide them with risk information and training is now 80 decibels.
So, making the right, well informed decision is as important for the self-employed as it is for employers.
As an employer, you have to provide your employees with properly maintained hearing protectors if they ask for them and if their noise exposure is between the lower and upper exposure thresholds. You also have to make sure they use them properly and establish hearing protection zones where the use of hearing protection is compulsory.
Don't Take Your Hearing For Granted
Too often we take our health and wellbeing for granted and probably never stop to consider what fantastic sensory organs our ears actually are. As well as helping us communicate, our hearing helps to keep us safe. It is the link to our surroundings and is vital for how we communicate with others.
Aside from issues with your mobile phone, think how you’d cope in hazardous situations if you couldn’t hear an alarm bell, a car horn or someone calling to you. We rely on our hearing in so many ways, which is why we should protect it.
Unfortunately, for a significant part of the population, this ability is partially or entirely lost, because of exposure to loud noise. Hearing loss can never be restored but avoiding damage to your hearing is in most cases a matter of selecting and wearing the proper protection.
Our hearing isn’t designed for many of the sounds we are exposed to today especially the unwanted sounds - those that can potentially damage your hearing. So remember, if you need to raise your voice or scream to be heard when standing about meter from someone on site – then its more than likely that the noise around you is dangerous!
Noise on site
Sites are noisy places. Not just your mates banter and the radio in the background, but the working environment. Machine tools and plant all make noise, so does the process of using tools and applying fixings. It’s constant, almost incessant.
Working on site all the day means that noise is constantly being poured into your hearing. But what many people don’t realise is that every noise source and the length of time you’re exposed to it has an exposure level measurement and you’ll be surprised how quickly you can reach the maximum daily safety exposure dose without proper protection.
For instance, drilling into wood at 92 decibels would only give you 10 minutes safe exposure against your full day’s allowance!
Drilling into metal creates 96 decibels of noise, a chain saw 99 decibels, a circular saw 101 decibels, drilling into concrete 108 decibels and an angle grinder 109 decibels.
So take a look at the chart above and you’ll see that if you haven’t got proper hearing protection, you shouldn’t be on site working and handling tools for very long at all!
Peter Dumigan is managing director of the Hultafors Group UK, owners of Snickers Workwear, Solid Gear Safety Footwear and Hellberg Safety PPE. For more information, visit www.hellbergsafety.com
Definition of noise
What we call “noise”, is usually described as sounds we experience as unpleasant or disturbing. High level of noise is hazardous to your hearing. Noise can also lead to stress symptoms, discomfort and pain. Harmful noise is everywhere. Loud music, a rock concert, motorsports, target practice or hunting, even mowing the lawn – it could all damage your hearing.
Noise can be continuous, intermittent, impulsive or variable depending on how the noise changes over time or how a person moves in a noisy environment.
Steady continuous noise does not vary over time. In the industrial environment, the sound of a rotating electric motor (a fan, pump etc.) can be classified as steady continuous noise. Fluctuating continuous noise change level or/and frequency over time. Most manufacturing noise is fluctuating.
Noise is intermittent if it stops and starts at intervals. One example of intermittent noise is a compressor.
Impulse noise is characterized as a short pulse (<1sec) with very fast rise time and a level of at least 20dB above the continuous noise level.
Impulse noises are very dangerous to hearing. The brain needs at least 0,3 sec to identify a sound at the right level. The hearing organ reacts a lot faster. We do not realize that these noises are harmful to our hearing and we often disregard the need for protection. Examples of sound sources giving impulse noise are gunfire and hammer blows.
Hazardous noise affects the functioning of the hair cells in the inner ear leading to impaired hearing ability.
Hearing may be restored after a period of time away from noise but with further exposure the hair cells will gradually die and the hearing loss will become permanent.
Permanent hearing loss can also oc- cur suddenly. Exposure to one single impulse noise is enough to destroy the inner ear of an unprotected hearing organ.
Damage hair cells cannot be replaced or repaired by any known medical treatments or technology.
Different groups of hair cells are responsible for different frequencies. Hazardous noise first affects the ability to hear high-frequency (high-pitched) sounds. Humans are most sensitive to sounds near 4000Hz (the frequency band for speech) and this is the area where most hearing loss occurs.
Noise induced hearing loss often leads to tinnitus or hyperacusis. Tinnitus is commonly described as a ringing in the ears and it may be soft or loud, high pitched or low pitched. Hyperacusis is characterized by over-sensitivity to certain frequencies.
Other dangers with hazardous noise are high blood pressure, stress, negative social effects, headache, depressions and irritation.
Exposure to certain ototoxic chemicals can also affect hearing. Many sectors with high exposures to noise also have high exposures to dangerous substances.
Some people are more sensitive to noise than others. High temperatures, exposure to vibrations or having a cold increase the risk of hearing damage.