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  • Writer's pictureNeal Muggleton

What is Noise-Induced Hearing Loss?

Updated: Dec 27, 2023

Understanding the causes and impact of NIHL, and how to prevent it.

Man holding ear with concentric red rings overlaid indicating hearing damage
NIHL is not age related and cannot be seen

Noise-induced hearing Loss (NIHL) is hearing loss caused by exposure to a harmful level of noise. In the UK alone, NIHL caused by exposure to occupational noise (noise at work) affects over two million workers. Globally, a staggering 1.1 billion people are estimated to have the condition, with 16% of disabling hearing loss worldwide being attributed to exposure to occupational noise. Workers in industries such as manufacturing, mining, and construction are at particularly high risk of experiencing NIHL, which is a permanent and disabling condition.

To put the scale of NIHL into perspective, consider measuring the impact that hearing loss has on an individual, a community, or on society in general in years lost to ill health, disability, or early death. This international standard is called the Disability-Adjusted Life Year, and when it comes to hearing loss, current data estimates that over 4 million DALYs can be attributed to over-exposure to occupational noise. In sum: nearly one-fifth of the world’s population stands to lose a combined 4 Million years of life (or quality of life) as a direct result of exposure to unsafe levels of sound in the workplace.

In sum: nearly one-fifth of the world’s population stands to lose a combined 4 Million years of life (or quality of life) as a direct result of exposure to unsafe levels of sound in the workplace.

When it comes to monitoring and managing the risk from exposure to harmful levels of noise at work, it’s clear from these statistics that current approaches simply aren’t doing enough. 

In order to plot a better path forward, it’s important for teams to understand NIHL due to occupational noise: what causes it, how it impacts workers, and how to better prevent it. 

What causes or contributes to NIHL?

Occupational noise:

At work, NIHL is caused by exposure to harmful levels of noise in the workplace. Common sources of noise include powered hand tools, chainsaws, compressed air, and other heavy machinery and industrial equipment. Exposure to noise from sources like these can lead to NIHL. 

NIHL due to occupational noise can occasionally be caused by one-time exposure to an intense ‘impulse sound,’ like an explosion. But for most workers, hearing loss is cumulative, meaning it occurs over time. This is important because it means that hearing loss often occurs gradually, making it difficult to detect until it’s already problematic, and irreversible.

Hearing loss often occurs gradually, making it difficult to detect until hearing loss is already problematic, and irreversible.


NIHL is hearing loss caused by exposure to harmful levels of noise. But there are other factors that might contribute to - or accelerate - hearing loss that employers and safety managers should be aware of. 

In the UK, workers who perform shift work are more likely to experience hearing loss than non-shift workers. This is because shift workers are especially prone to various negative health outcomes, such as insomnia, cardiovascular complications, and decreased cognitive performance, all of which have been shown to aggravate noise-induced health problems, such as hearing impairment.

Moreover, occupational noise can increase mental workload, which can exacerbate the effects of noise on workers. This means that workers who suffer from an increased mental workload are at higher risk of worsening hearing impairment. 

This is of particular concern in the construction and manufacturing sectors: Research carried out in 2021 determined that construction was the most burnt-out industry in the UK, followed closely by manufacturing. The research identifies work pressure, long hours, and heavy workloads as driving this outcome.

Exposure to vibration:

Shift work and workload are two factors that might contribute to hearing loss due to the physical and mental strain they put on workers. But NIHL can also be accelerated or compounded when a worker is exposed to other sources of risk, like vibration, which have been proven to directly impact hearing loss.

When combined with exposure to occupational noise, exposure to vibration from sources like power tools or heavy equipment has been established as a possible risk factor for developing hearing loss. In fact, “[n]umerous studies have reported the combined effects of noise and vibration.” 

For many, if not most workers in the construction or manufacturing industries, exposure to both noise and vibration is a daily occurrence. Given the frequency with which NIHL occurs in these sectors, combined with their dangerously high rates of burnout and shift work (which have a demonstrable impact on hearing loss among workers), it’s especially important that teams and organisations find a solution to noise monitoring in the workplace that’s robust, and capable of addressing these unique circumstances in order to drive more meaningful outcomes.

How does NIHL impact workers, employers, and the economy?

NIHL due to occupational noise is often cumulative, meaning it gets worse over time. As a result, workers may not realise that they are having trouble hearing due to how gradually the condition sets in. This means that many workers don’t know they have NIHL until it’s too late: At this point, the symptoms and consequences can be far-reaching.

When workers experience hearing loss, it can interfere with their ability to safely perform their job. For example, someone with hearing loss might have trouble hearing safety warnings, or coworkers. Further, hearing loss may result in a worker making an NIHL-related claim against their employer: In recent years, there’s been a significant rise in these claims, resulting in colossal costs to insurers, and employers.

Outside of the workplace, NIHL impacts an individual's ability to communicate and interact with others normally. It’s not uncommon for hearing loss to go undiagnosed or untreated, which often leads to other serious or debilitating health issues like depression, social isolation, and cognitive decline, including an exponentially increased risk of dementia. In fact, the connection between hearing loss and negative health outcomes is so profound that hearing loss is categorised as the fourth-leading cause of disability worldwide, and it’s estimated that over 430 million people around the world require rehabilitation for disabling hearing loss. 

The connection between hearing loss and negative health outcomes is so profound that hearing loss is categorised as the fourth-leading cause of disability worldwide

In the UK alone, the overall impact of hearing loss on the economy - including lost wages, healthcare, and rehabilitation - has been estimated at an absolutely astonishing £25 billion. In light of these figures, and the debilitating impact of hearing loss on individuals and society, it’s clear that better solutions for combatting NIHL are urgently needed.

How can I prevent NIHL?

It’s important to note that NIHL is preventable. Employers need not view noise monitoring in the workplace as merely mitigating a known issue. On the contrary, a more proactive approach to noise monitoring helps employers address the issue of noise in the workplace before it leads to negative health outcomes for workers.

A more proactive approach to noise monitoring helps employers address the issue of noise in the workplace before it leads to negative health outcomes for workers.

In the UK, employers are duty-bound to protect their workers from exposure to unsafe levels of noise. The Control of Noise at Work Regulations 2005 lays out the specific responsibilities that employers have when it comes to monitoring and managing their noise environment. 

Traditionally, employers have aimed to meet these requirements by carrying out noise assessments at the workplace. During a noise assessment, a professional will visit the workplace and determine the average levels of noise in a given environment, as well as estimates of the personal daily noise exposure of employees. Following the assessment, they will offer recommendations and information regarding controls, hearing protection programmes, health surveillance, and PPE.

In light of the current landscape with regards to NIHL and noise in the workplace - which includes higher rates of NIHL-related claims against employers, thousands of new NIHL cases reported every year, and millions of affected workers - it’s clear that traditional assessments aren’t doing enough to effectively combat NIHL due to occupational noise.

What teams need is a solution for noise monitoring that not only measures exposure to noise, but also provides critical insight that informs better, more impactful decision making.

Smart Alert by Minuendo:

Smart Alert by Minuendo is a purpose-built solution for better overall sound monitoring in the workplace. Lightweight and easy to use, it was created to fully prevent exposure to unsafe levels of sound by alerting workers, in real-time, to unsafe conditions. Using cutting-edge, industry-defining technology, Smart Alert continuously measures a workers’ exposure to noise from inside the ear. Unlike traditional noise assessments, Smart Alert measures the amount of noise that a worker is actually exposed to, it doesn’t estimate exposure based on a calculation of average noise levels in a workplace. 

Crucially, Smart Alert does more than notify workers to unsafe levels of exposure, it also collects and collates data in an ultra-secure Cloud environment before automatically transforming it into actionable intelligence that can be used to facilitate better decision making, and better ways of working.

With this insight available in an attractive, dashboard-style format, your team can easily and quickly identify problem areas and hotspots, patterns and trends, and more. And since NIHL doesn’t exist in a vacuum, this additional context is mission critical when it comes to driving better health outcomes for workers. For example: with the insights you’ll get from Smart Alert, you might be able to identify that certain shift workers are experiencing higher levels of noise exposure than other employees. Or, you may be able to overlay your data from Smart Alert with information you have about your workers’ exposure to risk from other sources, like vibration.

Armed with this information, Safety Managers and duty holders can take swift, decisive action to improve or implement controls, reevaluate their resource allocation or ways of working, or take steps to ensure that their PPE is functioning properly, and being used appropriately. 

Reducing the instance of NIHL due to occupational noise starts with improved noise monitoring in the workplace. 

To see how Smart Alert can evolve your approach to noise monitoring and drive better outcomes for your workforce, you can schedule a demo. Just choose a time slot that works for you on this calendar. And if you’d like to chat with us to learn more about Smart Alert before you book your demo, feel free to contact us using these details.

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