Despite the fact that the pandemic has pushed many of us to embrace the outdoors in new ways—whether to safely meet with friends, family and colleagues, to exercise, or to embrace a new hobby—we still spend the vast majority of our lives (over 90 percent!) indoors. This reality points to the importance of healthy buildings, the impact of which reaches beyond physical or environmental factors, affecting not just individuals, but also organizations.
Elements such as noise, access to light and views, thermal comfort, the incorporation of nature, and healthy materials are shown to increase cognitive function, resulting in improved productivity among workers, higher test scores for students and quicker recoveries for patients. A healthy building can also impact a business’s bottom line—from energy reduction to more efficient and engaged employees. According to a recent World Green Building Council report, 69 percent of owners report improved worker satisfaction due to their healthier building investments, and 46 percent of commercial building owners say that they are able to lease space in buildings with healthy features more quickly.
Acoustics are one of the major contributing factors to a building’s overall health. While all building types are affected by acoustics, their effect is felt most strongly in workplace and healthcare environments. In the workplace, noise pollution leads to decreased productivity, absenteeism and dissatisfaction among employees, resulting in a massive financial burden for companies; whereas in hospitals, noise negatively impacts both patient recovery as well as staff performance and satisfaction, taking an enormous toll on patients, families and staff. This post explores the implications of noise in the design of workplace and healthcare environments.
Noise Reduction in the Workplace: Counteracting the Sound of the Human Voice
At the most basic level, we cannot ignore the sound of the human voice—it’s a survival mechanism. However, research tells us that voices over 55 decibels (roughly the sound of a loud phone call) can cause measurable stress. In the office, it is almost impossible to tune out the various conversations, phone calls and Zoom meetings. Because we often hear only one side of a conversation, our brain works tirelessly to fill in the other half—a concept called a “half-alogue” that can be even more distracting than other disruptive office noise. By contrast, a modest level of unintelligible background noise actually helps concentration in the workplace. So rather than aiming to reduce all noise, focus on materials and systems that specifically dissipate speech sounds. Here are four ideas to do so:
- Build it in: Think about sound reduction strategies that can be built directly into a space. For example, we worked with the University of Washington* to develop an acoustic panel system that can be embedded into concrete and mass timber structural systems. Shaped like empty bottles, these sound dissipating systems muffle noises and are highly effective at trapping low-frequency, intelligible sound due to their narrow necks and wide empty cavities. Tests of prototypes measured noise reductions of around 13 decibels, the equivalent of wearing noise-canceling headphones. Alternatively, consider prefab: conference rooms and other spaces that are regimented in size can be prefabricated to include acoustic solutions rather than relying on materials applied post-construction. Because each module is prepared as a separate unit with its own walls, floor, and ceiling, panels can be fabricated or milled in advance to directly address the preferred room acoustics and reduce both time and waste.
- Isolate the noise: Create insulated quiet zones within work areas, each with a target decibel level based on the type of work being done there. Nooks made of soft materials such as felt, or phone booths with soundproof glass can serve as quiet areas within a larger, more open office, and adding transitional cues through materials, light and volume reinforces the intent for each zone.
- Incorporate biophilia: Not only does being around nature improve our mood and make us more productive, but plants are also incredible natural sound absorbers. While a green wall is excellent for capturing sound, even greenery dispersed throughout the office can help mitigate noise.
- Not all noise is bad noise: While spaces that are too loud can be stressful and distracting, those that are too quiet can feel awkward and uncomfortable — or even drive you crazy. Aim for the din of a coffee shop, where noise is ambient but not distinguishable.
Noise Reduction in Healthcare Environments: Promoting an Atmosphere of Rest and Focus
As in the workplace, heightened noise levels in healthcare settings have a strong negative effect. Researchers at Johns Hopkins University found that excessive noise not only hindered patients’ ability to rest, but also increased the likelihood of medical errors and contributed to stress-related burnout among workers. One example of noise reduction that has stood the test of time is Massachusetts General Hospital’s Lunder Building, which was completed in the 2000’s. The building combines design innovation with changes in clinical practice to reduce average noise levels by 35 percent as compared to the worldwide average. To design quieter healthcare environments, consider these five solutions:
- Move activity away from patient rooms: Many challenges related to noise in healthcare environments have to do with issues of proximity and speed. Caregivers need to be close to patients, teams and families to provide the highest quality of care, so while it is beneficial to design units that place patients near caregiver teams, it is equally important to remove other sources of noise—such as mechanical equipment, closing doors, ice machines and cart traffic—from outside patient rooms.
- Tailor clinical team work spaces for appropriate visibility and noise levels: In hospitals, clinical teams on patient floors are getting larger, there are more interactions happening amongst various care team members—both in-person and remotely—and information is constantly being updated. Caregivers must be able to focus, pivot and think on their feet to stay on top of their tasks and patients. By providing enclosed team work areas and space for heads-down concentration, while ensuring that staff can still see their patients and converse, caregivers are able to perform at a high level without noisy distractions.
- Remove rounding teams from corridors: In academic medical centers, rounding teams often conduct impromptu conversations or teaching moments in corridors outside patient rooms. And while these types of walking meetings are beneficial for many reasons, the noise that comes with them is not. Designing alcoves that take teams out of earshot helps to maintain an impromptu, informal atmosphere while increasing privacy and significantly reducing noise.
- Take cues from lighting: Ambient lighting is an unexpected way to suggest how quiet or noisy a particular area should be. The way that corridors and nurse stations are lit during certain times of day—for example, brighter in the morning and dimmer at night—can indicate the appropriate voice level to staff, in addition to supporting staff members’ circadian rhythms and creating a more calming atmosphere, both of which are important in managing stress.
- Explore materiality: Absorptive materials are often overlooked in healthcare settings because they may appear difficult to clean. However, rubber flooring, antimicrobial fabric panels or even quieter cart wheels can all help to dissipate sound.
Designing a healthy and acoustically sound environment is a delicate balance of transparency and privacy, concentration and energy. By creating thoughtful spaces that consider how noise affects rest, stress and productivity, we can achieve buildings that are healthier for those that occupy them.
*Copyright 2022 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. This article appeared in The Journal of the Acoustical Society of America 151, 457 (2022) and may be found at https://doi.org/10.1121/10.0009317.Follow nbbX