How Does Hearing Loss Occur?

How Does Hearing Loss Occur?

Work related hearing loss is an irreversible yet preventable condition. Exposure to a high decibel workplace environment can permanently damage hearing. The delicate hair like cells found in the inner ears send messages to the brain. Sound stimulates these cells, and hearing damage can occur when excessive noise damages these cells.

Causes of hearing loss can include extended exposure to hazardous noise or exposure to a very loud impact or explosive noise.

The standard for noise exposure in the workplace is;

  1. Workers cannot be exposed to a noise level above 85 decibels over an eight-hour period

  2. Workers cannot be exposed to a noise level above 140 decibels as hearing damage can occur almost instantly above this level

Long term exposure is the more common reason for hearing loss rather than ear damage from a loud noise. Hearing loss can also be caused by other workplace risk factors such as vibration and ototoxic substances (chemicals that can result in hearing loss). Noise induced hearing loss cannot be cured and worsens if hazardous noise exposure continues.

Workplace noise needs to be reduced to a level where the risk of hearing damage is minimised, either by implementing control measures or through hearing protection. Determining the best hearing protection for your workplace can be challenging as noise hazards are sometimes not obvious but as a rule, noise levels should be kept below 50 decibels if work requires concentration or effortless conversation. If work is routine, fast paced, demands attentiveness or is important to carry conversations, noise levels should be kept below 70 decibels.

In-ear noise levels should generally be kept between 75 and 80 decibels, as at 85 decibels the noise can cause damage and 70 decibels is considered over protection. Below is a decibel comparison table outlining decibel levels and corresponding common noises to illustrate the level of noise workplaces need to maintain when attempting to prevent hearing loss for workers.

Painful to Faint Noises

The one-metre test is also a good indication of safe noise levels. If you need to shout to communicate with someone who is standing one metre away from you, you can assume that the noise level is dangerous.

If workplaces operate above these standard noise levels, the risk of hearing damage for workers is increased. According to the Australian Government Department of Health, in Australia, 3.6 million people suffer from hearing loss and 1.3 million people have a hearing condition that could have been prevented. Hearing loss symptoms can have a serious effect on a person’s quality of life. It can contribute to dementia, stress, hypertension, tinnitus (ringing in the ears) and some psychiatric disorders. Untreated hearing loss has also been known to increase the risk of memory loss and depression. In the workplace, hearing loss can lead to safety problems as it can cause a lack of awareness and reduced concentration. It can also lead to difficulty with communication whilst wearing hearing protection, making the worker less inclined to wear hearing protection which can then lead to greater hearing damage.

It’s important to note that a one size fits all process is not always an effective control measure and that the risk and task should be assessed and the appropriate hearing protection should be selected after completing a noise audit. It’s vital that the wearer is also aware of the correct method of fitting the appropriate PPE as failure to comply with this process will limit the correct levels of protection as a result.

According to Safe Work Australia, 28-32% of the Australian workforce are likely to work in an environment where they are exposed to loud noise. Issues with hearing loss or damage are most common in the manufacturing and construction industries. One third of all claims made in 2015 were from workers in the manufacturing industry and 18% were made by construction employees. Technicians, trade workers, machinery operators, drivers and labourers are most at risk.

On average, there are 4,700 claims made per year for noise induced hearing loss, with 16% of these claims lodged by trades persons in the automotive and engineering industries. Long term exposure to hazardous noise from working inside is the primary cause for all of these claims.

Extended exposure to hazardous noise in the workplace can lead to permanent hearing loss or tinnitus which can have debilitating effects. However, it is also the most preventable cause of damage. If workers at risk are identified and control measures are introduced, the risk of damage is minimised. These limits should protect most, but not all, workers so it is important to carry out continued assessments of noise levels in the workplace. Ensure hearing protection is being worn consistently and correctly, no matter what types of hearing protection are being used, to ensure you are operating at a safe level. For assistance with workplace noise assessments and finding the best methods of noise reduction, contact the team at ATOM Safety.

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