It's well established that a quiet environment promotes healing. Yet, the noise levels of the places built for healing and recovery in the United States have been steadily increasing since the 1960s and are more than double the acceptable level (1). From the beeps and whirs of machines to conversations among the staff, noise is one of the main disruptions to patients in health care settings (2). Unwanted sounds are more than a little annoyance; studies show elevated noise can affect sleep, injury recovery, cognitive processing, mental performance, and more (2).
The World Health Organization (WHO) recommends the average noise in hospitals should be no higher than 40 decibels (dBA) during the day and 30dBA during the night. However, many hospitals are unsuccessful at meeting this range, with the worldwide average sitting at 72dBA (2, 3). Additionally, one of the lowest scoring items on patient surveys in the US is "quietness of [the] hospital environment" (4).
Noise Impacts on Intensive Care Units
In intensive care units (ICUs), noise is among the most distracting environmental stressors patients encounter (5). For example, the alarms that monitor patients often exceed 70 dBA, the same sound level as highway traffic (5). Other studies have found ICUs exceeding 100dBA, comparable to loud music played through headphones and past the point of causing hair cell damage to the inner ear (6, 4). As a result of the loud machines, staff increase their speech volume to be understood, further contributing to a noisy environment that prevents patients from having a good sleep (5). A 2012 study exposed ten patients to various noises and found that they all had interrupted sleep (2), leading to reduced energy levels and impaired cognitive functioning and recovery (2). The lack of sleep from the alarms and other sounds may also contribute to agitation and ICU delirium - a condition that affects the brain of critically ill patients and contributes to ICU morbidity and mortality (7, 8).
Patients may also be more likely to request a premature discharge if they've spent several nights in a noisy environment, which increases their risk of poor recovery and readmission (4). In a Swedish study, 94 patients were admitted to an intensive coronary heart unit to evaluate chest pain. The patient groups were admitted into the hospital during different acoustic treatment levels within the unit. During the study, the sound levels were altered by changing the ceiling tiles from sound-reflecting tiles that created bad acoustics to sound-absorbing tiles that produced good acoustics. Afterward, the patients completed a questionnaire about their quality of care and rehospitalization. The study found coronary care patients treated during noisy periods had a significantly higher incidence of rehospitalization than those treated during quieter times. Patients treated when the sound-absorbing ceiling tiles were in place also believed the staff attitude was much better than the group treated with the sound-reflecting tiles (9). This is likely because the employees experienced benefits from the noise reduction, too.
Constant exposure to noise has been found to impact the quality and safety of care staff provide to patients. Annoyance, irritation, and fatigue can affect staff well-being and lead to burnout (6). Additionally, unwanted noise stresses the nervous system and increases cortisol levels - the stress hormone. This, in turn, can alter the brain and inhibit staffs’ ability to communicate and connect with others (10).
Noise Impacts on Babies in NICU
A noisy environment can also affect infants and children. Studies have found that constant exposure to loud sounds may affect children's cognitive development (11). A recent review study looked at sound levels in the neonatal intensive care unit (NICU). It found that neonatal infants in the NICU are subjected to sounds louder than most home or office spaces. The American Academy of Pediatrics recommends sounds in the NICU not exceed 45dBA, but levels have been found to range all the way up to 120dBA (12).
Additionally, 2 to 10% of preterm infants are diagnosed with hearing impairment compared to 0.1% of the general pediatric population. The elevated sound may contribute to apnea, hypoxemia, changes in oxygen saturation, and increased heart and respiratory rates, reducing the number of calories available for growth. Similar to the ICU, the high-intensity sound in the NICU results in louder communication, which negatively impacts the staff, newborns, and their families. As a result of the high noise levels, staff may have more errors and accidents (12). Some possible solutions that have been proposed to lower the sound levels in the NICU include treating the infant in a private room or in incubators that have controlled sound levels or using earplugs to reduce the sound the infant experiences (12). Reducing the noise in the NICU can help diminish stress and promote growth (12).
Airplane & Traffic Noise
It's not just in a healthcare setting that constant noise can cause serious health consequences. For example, a study by the Harvard School of Public Health and Boston University School of Public Health found that individuals exposed to high levels of aircraft noise were more likely to be admitted to the hospital for cardiovascular reasons (13). This hospitalization is because unwanted sounds can increase stress and blood pressure, which are linked to heart disease (13). There is also evidence that patients exposed to noise may experience reduced sleep quality, cognitive processing, speech, and overall psychological well-being (2). Additionally, a 2019 review of traffic noise effects on health found road-traffic noise increases the rate of depression and anxiety and is a significant risk factor in developing cardiovascular disease. It was found that for every ten dBA increase of noise starting at 50 dBA, the risk of coronary heart disease jumps 8% (14).
Proposed Acoustic Solutions
Although we can't control all environmental noises and their consequences, we can help hospitals create a healthier, quieter environment for their staff and patients. For example, our sound-absorptive ceiling baffles placed in waiting rooms and common areas help reduce reverberation time - the time it takes for noise to fade - and ultimately help minimize noise. The ceiling is often the largest surface in a facility, so a sound-absorptive ceiling can help reduce the distance noise and conversations can travel (8). Studies also recommend hospitals invest in other noise-reduction materials, including double-glazed windows, floors, and walls, and use materials with strong noise-absorbing abilities to help reduce echoes (2). Sound-absorbing carpets can reduce ambient noise by up to 70%, and architects are also looking at reducing noise in the way the infrastructure is designed (5). A study that placed sound acoustic panels in a hallway found the noise was reduced by 3-4dBA compared to the control hallway (15). Sound masking - the addition of background sound like white noise - may also reduce noise-related disturbances and has been shown to improve sleep in hospitals (4).
The Massachusetts General Hospital Lunder Building is proof that soundproofing creates a better space for both staff and patients. The building uses various methods, including rubber flooring and acoustic ceiling tiles, to reduce average noise levels. Interviews showed patients were sleeping better, and staff performance increased (16). The decibel levels on the patient floors were on average 46.5dBA, or 35% lower than the worldwide average, and perceived to be six times quieter by the human ear (3).
At FSorb, our goal is to improve health by using environmentally friendly and aesthetically pleasing designs to minimize impacts to the nervous system. The evidence is clear that soundproofing healthcare spaces can help reduce the many health-related consequences of a noisy environment. We understand that infection control requirements in varying jurisdictions often limit what materials can be used in patient rooms. In some cases, we may need to wrap our panels with a washable fabric. Please contact us to collaborate on various types of sound-absorbing solutions using FSorb. Let us reduce the negative side-effects of noise and help you reach your acoustic goals with our eco-friendly panels.
At FSorb, we are motivated by improving human health and do so by creating eco-friendly acoustic products. Our mission is to help designers build beautiful spaces that reduce excess ambient noise while calming the human nervous system. With over 25 years in the acoustic business we stand behind FSorb as a durable, environmentally friendly, and low-cost product. If you want an acoustic solution that is safe to human health at an affordable price, then we are your resource.
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Delaney, L., Van Haren, F., Lopez, V. (2015). Sleeping on a problem: the impact of sleep disturbance on intensive care patients - a clinical review. Annals of Intensive Care, 5(3). doi: 10.1186/s13613-015-0043-2
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Hagerman, I., Rasmanis, G., Blomkvist, V., et al. (2005). Influence of intensive coronary care acoustics on the quality of care and physiological state of patients. International Journal of Cardiology, 98(2), 267-270. doi: https://doi.org/10.1016/j.ijcard.2003.11.006
Poor Acoustics Inhibit Human Connection. (2017, July 19). Retrieved January 19, 2022 from https://www.f-sorb.com/post/poor-acoustics-inhibit-human-connection
Klatte, M., Bergstrom, K., Lachmann, T. (2013). Does noise affect learning? A short review on noise effects on cognitive performance in children. Frontiers in Psychology. doi: https://doi.org/10.3389/fpsyg.2013.00578
Almadhoob, A., Ohlsson, A. (2020). Sound reduction management in the neonatal intensive care unit for preterm or very low birth rate infants. Cochrane Database of Systematic Reviews, doi: https://doi.org//10.1002/14651858.CD010333.pub3
Correia, A., Peters, J., Levy, J., et al. (2013). Residential exposure to aircraft noise and hospital admissions for cardiovascular disease: multi-airport retrospective study. The BMJ. doi: https://doi.org/10.1136/bmj.f5561
Hahad, O., Kröller-Schön, S., Daiber, A., & Münzel, T. (2019). The Cardiovascular Effects of Noise. Deutsches Arzteblatt international, 116(14), 245–250. https://doi.org/10.3238/arztebl.2019.0245
Farrehi, P., Nallamothu, B., Navvab, M. (2015). Reducing hospital noise with sound acoustic panels and diffusion: A controlled study. BMJ quality and safety, 25(8), 1-3. doi: 10.1136/bmjqs-2015-004205
Hospital Design Changes To Reduce Noise Could Also Help Lower Stress Among Patients and Staff. (2021, October 6). Retrieved January 19, 22 from https://www.forbes.com/sites/coronavirusfrontlines/2021/10/06/hospital-design-changes-to-reduce-noise-could-also-help-lower-stress-among-patients-and-staff/?sh=73d206e95783