Noise is not just loud sounds – The Science behind Workplaces that Work

Ayat Ismail

1 November, 2022

As a business owner seeking the consultation of a workplace design specialist, you will be faced with a number of recommendations that are crucial for the work environment to support your business. Yet you may keep wondering, “Do I really have to pay for sound absorbing panels? Why go for an expensive material for better office acoustics, while I can save up on a cheaper one? What is the big fuss about sound barriers anyway? I just don’t want to pay for extra accessories that I can do better without.” Well, let me tell you that, “These design solutions are not a luxury. They are in fact sparing you and your business from a multilayered problem called ‘ambient noise’.”You may then retort, “So what? We live in a noisy world, the ambient noise in any city around the world exceeds the average values that humans can tolerate anyway.”

Time to translate this vague word ‘noise’ into costs and benefits, what are the costs of not dealing with ambient noise levels inside the workplace? Are the long-term benefits outweighing the initial cost? The costs of noise can inspected against 3 main aspects. First: the impacts of noise on employees’ productivity and concentration levels. Second: the impacts of noise on employees’ physical health and vulnerability to illnesses. Third: the impact of noise on the social interactions between employees and the overall office culture. This post discusses these impacts and possible strategies to mitigate these impacts. Let’s first begin with defining what noise is.

Is it Sound? Or is it Noise?

Not every sound classifies as noise. You might think that loudness of the sound is the only thing that makes it noise. In fact, there are four different characteristics of sound for it to be considered as noise.

  1. The loudness of the sound: This is determined by the sound pressure level in the place. This is measured in dB(A); that is an adjusted logarithmic scale of decibels that considers the varying sensitivity of human ear to different frequencies of sound. Ambient noise in open workspaces should range between 45-48 dBA and between 40-42 dBA in enclosed offices according to WELL Building standards. Otherwise, the work environment is too noisy for intellectual tasks to be performed.
  2. The intelligibility of sound: This determines the distracting power of ambient speech. It is measured using the Speech Transmission Index (STI). Studies show that work performance of focused tasks is best when speech is absent (STI=0.00) and worst when speech is perfectly understood (STI=1.00). Imagine the situation where a team of employees talking together on some collaborative task and near by sits others colleagues focusing on a task independently. While the team members need to be able to hear each other, other colleagues in the space could get distracted from their task at hand, if they are able to clearly comprehend the speech of the team. In this sense, speech becomes noise if the sound level is not loud.
  3. The perceived control over sound: When people feel that they have no control over the source of the noise (lower the volume, change the channel, or hush a coworker for example), thensounds become agitating noise. In contrary to loud sounds that can be controlled, which people do not usually perceive as noise, it is more of a choice.
  4. The predictability of sound: Sound becomes agitating noise when it bursts suddenly, in an unpredictable time and with no clear pattern. Nonetheless, dull sounds that are repeated non-stop can be agitating even if it follows a predictable pattern, just like the sound of water drops from a leaking faucet.

Now imagine, an employee working in a place where they are exposed to high levels of sounds, high levels of sound intelligibility, facing low levels of perceived control over sound and low predicability of sound. That is when sound becomes noise. Now, let’s move on to discussing the impacts of ambient noise on productivity, health and social interaction at the workplace.

A – Ambient Noise & productivity

Exposure to noise could have serious implications for both the employees and the organization altogether. In a 2017 research on wellbeing and productivity, noise levels were identified as a major component directly affecting the wellbeing of the users employees and indirectly impacting the overall profitability of the companies. This is aligned with the findings of the World Green Building Council report of 2014, that showed that noise distractions resulted in a 66% drop in performance and concentration. In the same year,75% respondents of the Leesman index of 2015 considered the noise levels an important part of an effective workspace, with just about 30% satisfied somehow with their current noise levels in their workspace. Therefore, the impacts of noise levels can not be ignored.

But why is that? Studies from Place Science shed some light on this phenomenon. A famous study done is the 1980s may give us some idea on the impacts of noise exposure. The study examined the impact of aircraft noise on a school, located under the aircraft’s runway path in Los Angeles Airport. The first part of the study showed that under these conditions, pupils were unable to perform cognitive tasks like comprehension or problem solving. They also tended to give up on completing tasks due to their inability to sustain attention long enough for the task to be completed. In the second part of the experiment, the same pupils were tested again a year later. This time the walls and roof of the school was insulated to reduce noise inside the classrooms to acceptable levels. The results of the pupils showed an improvement in cognitive performance and concentration.

It is clear by now how the exposure to noise contributes to workplace stress; leading to severe drop in productivity and concentration of employees. However, the story does not end here.

B – Ambient Noise & Health

Ambient noise not only affects our psychological health. It has serious on our physical health. A study at Harvard Business School sadly found out the workplace stress is responsible for up to 8 percent of national spending on health care in the United States and more than 120,000 deaths per year.

But how is this even possible? First, let’s look how our body responds to stressful situations. As a natural coping mechanism, our body produces ‘Cortisol’ a.k.a. the primary stress hormone. When a person is subjected to prolonged period of stress, their body keeps releasing cortisol. This eventually leads to an increase in blood pressure, a decrease in immunity levels among other major symptoms. This has been empirically proven by many studies. Take for example the study conducted on residents of a high-rise apartment complex built over the Bronx Expressway in New York City. Under the building, vehicles pass by in high speed producing high levels of loud, unpredictable and uncontrolled noise. The researchers found out that residents living on floors closer to the street level exhibited– on average – elevated levels of blood pressure. Whereas, the farther the floor from the street level – thus away from the high levels of noise – the less likely the residents develop physical symptoms.

Furthermore, the destructive side of stress is shown in the result of a striking experiment done in the 1990s. They divided the participants into two groups. The first was the participants who declared that they were under stress. The other group were these who declared that they were not under any kind of stress. For the sake of the experiment, all participants were exposed to the cold virus. The shocking result was that that group under stress showed severe cold symptoms; while the stress-free group showed mild to no symptoms at all.

So, we can safely say that noise leads to stress, and stress leads to physical illnesses. This would require continuous and expensive medical care or could lead unfortunately to death.

C- Ambient Noise & Workplace Interactions

Noise exposure not only affects the individual’s own productivity and health. It also extends to affect the social interactions. “Have you ever noticed you (or a colleague) acting out of character? Then when asked about what happened, you are unable to identify what got into you and made you so rude or anxious? Well, there is no mystery here, noise plays a major factor in our behavior.

Place scientists show us that the people’s behavior is subjected to change when there is noise around them. One experiment observed how noise level affects people’s sensitivity to social cues and their willingness to carry out their social responsibility. The study showed that people tend to help a man with a broken arm to carry heavy books on a calm residential street. But with a noisy loan mower turned on in a nearby yard, people started to avoid helping the same man with the same broken arm. They subconsciously want to get away from the noise as fast as possible.

Taking these findings to workplace sends warning signals on the affect of ambient noise on team dynamics, collaboration among coworkers as well as the overall social interactions at the workplace. Now this becomes problematic particularly with open-office spaces and activity-based workplace layouts . Open areas are now widely used to induce more interactions among staff, thus offering the space for collaboration and creativity. In fact, companies that have noise areas for interactions are reported to be considerably more profitable, according to a study of the effects of workplace conditions on productivity, creativity and profitability. However, the picture gets complicated knowing that open areas come also with the cost of ambient noise, that could – as established above – worsen social interactions.

Thus, it could be understood how ignoring ambient noise at workplace decreases social sensitivity and increases workplace conflict. This would negatively impact teamwork dynamics, cooperation between coworkers, and the overall behavior and attitude of all employees, eventually affecting the productivity and profitability. All of which could be avoided with the appropriate strategies to deal with ambient noise.

So, How to manage levels of ambient noise in the workplace?

To begin with, it is essential to recognise the two sources of noise at the workplace: externally generated noise and internally generated noise. Exterior noise refers to noise coming from the street outside the building. Whereas interior noise refers to noise generated from activities inside the workplace itself. In all cases, the first step of addressing noise is to conduct sound mapping.

Acoustic treatment of workspaces @ MRSOOL Workplace , Cairo, 2020
A – Strategies for Exterior Noise

When dealing with exterior noise, the first step is to examine the sources of exterior noise. Accordingly, Strategies to reduce the intrusion of exterior noise to the interior may include:

  • Using the adequate treatments and materials on the exterior walls of the building
  • properly sealed doors and window sections can highly contribute to reducing transmission of exterior noise.
  • Identifying the possible zones for various activities. For instance, if the workplace is looking over a busy street, you may consider locating quiet spaces away from the facade.
B – Strategies for Interior Noise

There are two broad sets of strategies when dealing with internally generated noise: design interventions and operational interventions.

Design interventions: addresses the physical design of the workplace at three levels: the workplace level; the intermediate level and the workspace level. These strategies include:

  • Acoustic planning addresses interior noise at the workplace level. It aims at identifying the potential sound disruptions expected from the various activities and equipment to be used in the workplace. Accordingly, an acoustic plan is developed – based on Activity-Based Workplace approach – to create loud zones and quiet zones. These zones give employees the choose to select loud spaces for collaboration activities as well as quiet spaces to focus when required.
  • Sound blocking addresses the intermediate level. It focuses on reducing sound transmission from one space to another. This is done using sound barriers such as high performance partitions and proper sealing of all doors and opening in the walls.
  • Sound absorption addresses the workspace level. focuses on reducing sound levels in a direct space where employees are working. This is done using sound reducing surfaces, such as installing high performance acoustic panels on ceilings and walls, sound-absorbing floors and furniture.

Operational Interventions: focus on covering the internally generated noise when the office is occupied. These strategies should be regarded as complementary measures and not a substitute of good acoustic design of the workplace. The operational strategies include:

  • Sound masking: This strategy uses sound-generation equipment to provide a steady background noise to cover acoustical distractions and proved to improve cognitive processes and performance. The facility managers may select from various sound frequencies or nature-based soundscape.
  • Office Etiquette: This strategy is about setting a clear standards to manage the behaviour of staff at workplace in terms of sound level. This for instance includes keeping their device ringers silent or on vibration mode, where to conduct phone calls, how to signal that they do not need distractions and so on.

According to the specific conditions of your workplace, the workplace design specialist will work with you to devise the optimum combination of strategies within your budget; that would help maintain the wellbeing of your employees as well as attaining your business goals.

In this post we discussed noise at workplace and its crucial role in the wellbeing and productivity of the workplace and how workplace design may contribute to mitigating the adverse impacts. Nevertheless, other aspects that may hinder or support the effectiveness of your workplace design among which are: crowding, color scheme, materials. Stay tuned for upcoming posts on this series of Stay tuned ‘The Science behind Workplaces that Work’ series for insights on other aspects that affect the productivity of your workplace.

References
  • Cohen, S., Evans, G.W., Krantz, D.S., Stokols, D. (1980) Physiological, motivational and cognitive effects of aircraft noise on children. Amercian psychologist. (35) 231-243.
  • Cohen, S., Tyrrell, D. A., & Smith, A. P. (1991). Psychological stress and susceptibility to the common cold. New England journal of medicine, 325(9), 606-612.( https://pubmed.ncbi.nlm.nih.gov/1713648/)
  • Hongisto V., Haapakangas A., and Haka M., (2008), ‘Task performance and speech intelligibility – a model to promote noise control actions in open offices’, Performance: 9th International Congress on Noise as a Public Health Problem (ICBEN). (http://www.icben.org/2008/PDFs/Hongisto_et_al.pdf)