When we speak about noise or hearing conservation at the work place, as health and safety practitioners, our mindset nearly always takes us to what we have learnt about controlling high levels of noise. We start going back to our tried and tested ways of measuring levels of sounds that are above the 85 Decibel level (The Magic Number!). We start looking at ways to minimize the high level of noise, reduce the amount of hours the workers spend in the noisy areas, choosing the suitable PPE that needs to used and considering Noise Reduction Ratings (NRR).
From a health point of view, we look for signs of Noise Induced Hearing Loss (NIHL) through periodical audiometric testing. Organizations start this when employees join the company for the first time and then have follow up tests after so many years as part of their medicals or as part of their final leaving process. Hearing conservation training is common place for many of the industries where operations may present considerable noise Hazards, as part of these training sessions, employees learn about the concepts of attenuation, hearing protection, double hearing protection and the importance of controlling noises above….you guessed it….85 Decibels (The magic number again!)
While all of the above is good, proven, and has eliminated and minimized many noise concerns throughout the years, our current methods unfortunately do not address what I would like to call the "twilight zone" of hearing conservation! I am talking about the noise levels between 35 to 85 decibels. These levels often get ignored at the workplace as it is below the threshold levels where employees are required to take action.
As I went through my various occupational health studies and took on assignments to manage noise at my various workplaces, the safety standards nearly always referred to controlling risk at high sound frequencies and rarely touched upon the chronic long term effects caused by noise at low or medium levels. This is where the health part comes into play, and having a Zero Harm work mentality will require teams to look at the long term adverse effects impacting general employee wellness. Effects which may not always be within the critical ranges of workplace noise levels.
Knowing such implication would require practitioners to look beyond the immediate risk and examining the health aspects in more detail. The World Health Organization (WHO) for example, provide a much more in depth analysis of the impacts of noise within those ranges. They also provide some interesting statistics to the extent of the issue with an estimated 30 billion pounds being the annual cost to Europe as a result of excessive noise, much of it of course, down to lost working days, health care costs and reduced productivity.
Noise between the 35 to 85 dB range can trigger the body's stress response. As a result, noise, at these levels, have been linked with health problems such as heart disease, high blood pressure and musculoskeletal problems. A Cornell University study on office noise, found that those working in noisy office environments can also be less likely to ergonomically adjust their workstations for comfort, contributing to other physical problems. Noise within the medium ranges can also impact sleep quality by preventing sleep and disrupting sleep cycles. And, perhaps most significantly, because chronic stress can lower your immunity to all disease, noise pollution is a general threat to employee wellness.
In the points below I have highlighted some of the key areas where even medium noise levels can have an adverse effect on general well-being and productivity within the workplace:
1. People will be less productive
A British Journal of Psychology study found that whether reading or writing, background noise will reduce productivity. In fact, experiments show that between the levels of 40 dB to 50 dB workers showed an astonishing 66% reduction in productivity.
Much has been said about open plan offices and its positive impact on moral and communication within the workplace. Collective noise within the medium levels does however remains a concern within these working environments and care must be given to ensure noise is managed in such work-spaces.
Dedicated quiet spaces, noise friendly flooring and sound friendly furniture, acoustic wall panels, cubicles and partitions, the occasional use of noise cancelling headphones are only some of the ways that noise can be reduced in open work offices.
Multitasking also becomes so much harder when strong background noise is present. With people using most of their energy to concentrate on the one thing in hand as a result of the surrounding influences.
2. Noise does cause workplace stress and reduces overall motivation
Scientists are in agreement that exposure to continuous noise can cause stress, even if we are not consciously aware of it. Noise triggers a stress response in the body which in turn affects mood, concentration and overall motivation.
3. Noise can impact physical health
As mentioned earlier, chronic exposure to medium level noise has been linked to heart disease, high blood pressure and musculoskeletal problems. The stress response triggered by noise can have long term health implications that go well beyond the hearing conservation concerns we traditionally focus on.
The message here is that we should not limit our noise management strategies to the high decibel ranges. The twilight zone of 35 to 85 decibels deserves attention too, as part of a holistic approach to employee health and welfare.