The ear is a conduit for engagement. Our sense of hearing enables us to connect with others, and any reduction in the ability to hear is experienced as a grievous loss.
When someone is diagnosed with noise-induced hearing loss (NIHL) they lose out on a vast canvas of life experiences, early symptoms include:
- People who are unable to be fully involved in the life of their family because they can’t hear what is said when more than one voice is talking at family dinners;
- people who can’t hear the breathy whisper of a child telling them a secret;
- people who can’t experience peace and quiet because of tinnitus, a persistent buzzing or ringing in their ears; are all losing out on a vast canvas of life experiences.
Yet when the words “occupational disease” are heard or read, few of us think of NIHL.
We think instead of respiratory illnesses or skin conditions, despite the fact that NIHL is one of the more common occupational diseases.
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Occupational noise causes 16% of disabling hearing loss
“Worldwide, 16% of disabling hearing loss in adults is attributed to occupational noise.” NIHL is a scheduled occupational disease – that is, there’s a presumption that if the employee is exposed to noise on the job, any hearing loss is a result of that noise – unless proven otherwise.
“Noise-induced hearing loss takes years to develop,” says Rand Mutual Assurance’s (RMA’s) Dr Ingrid Lesenyeho.
“Both ears are affected more or less equally and symmetrically, and it affects high frequencies first.” And that’s just where human communication takes place, as Deborah Nelson and colleagues wrote in their 2005 paper ‘The Global Burden of Occupational Noise-induced Hearing Loss’: “NIHL typically involves the frequency range (pitch) of human voices, and thus interferes with spoken communications.”
The damage caused by this continuous exposure to noise is irreversible – but if exposure to the noise ends, the damage does not get any worse.
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Follow advice and regulations
All of this explains why employers must follow recommendations and regulations around noise.
If your operation is a noisy environment, all employees working in that environment should have an audiogram before starting work, and all appropriate measures to protect their hearing should be taken.
The rule of thumb is that damaging noise is anything above 85 decibels, and that includes the sound of jet engines, lawn mowers, motorcycles, chainsaws, powerboats, and pneumatic drills, says Dr Deodat Kritzinger, General Manager: Medical of RMA.
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“If you have to shout to be heard by someone just an arm’s length away from you while the noise is going on, it is probably in the danger zone,” he explains.
Workers in factories, mines and construction, as well as heavy industry, are especially at risk, but NIHL can also affect police, military personnel (who are exposed to the sounds of gunshots and explosions), and musicians and entertainment industry professionals (rock and jazz musicians show high levels of hearing loss – but so do musicians in the field of classical music).
Anyone who will be working in a hazardous noise level should have an audiogram at the outset, so that you have an understanding of how good his or her hearing is before exposure.
Can NIHL be prevented?
The good news is that NIHL can be avoided by taking the necessary precautionary measures, such as:
- employees wearing hearing protective devices (HPDs) when exposed to noise; and
- employers taking the necessary precautions to reduce the sound at source (such as putting machines in a muffling housing, for example).
If you do have an employee with possible NIHL, here are a few valuable guidelines from RMA
- The baseline audiogram (which could have been performed at a previous employer) will give the employee’s level of hearing at the outset
- Another audiogram will be able to establish the degree of hearing loss
- You (or the employee) need to show that the employee is exposed to excessive noise in the workplace – greater than 85 decibels over an eight-hour day or 40-hour week. The higher the intensity of the sound, the less exposure time is needed for NIHL to occur
- You will need to show that the type of hearing loss is due to noise exposure and not the various other possible causes of hearing loss as confirmed in a medical report.
Red flags to watch out for
Some of the warning signs that an employee might have been exposed to hazardous levels of noise include:
- The individual cannot hear someone talking three feet away
- They have a feeling of “fullness” in their ears after leaving a noisy area
- They hear ringing or buzzing (tinnitus) in their ears immediately after exposure to noise
- They suddenly have difficulty understanding speech after exposure to noise;
- They can hear people talking but you have difficulty understanding them.
To avoid further or serious damage, it may well be worth alerting your employees to these warning signs and asking them to tell you if they are experiencing any.
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Sources: World Health Organisation; University of Witwatersrand; International Archives of Occupational and Environmental Health; Better Hearing