Too Noisy to Heal
Hospitals are noisy and stressful places. Most exceed the World Health Organization standards in average noise levels. A recent study showed that hospitals are getting noisier each year, with a growing cacophony of people, alarms, machines, and clattering carts.
1 This is particularly critical because so much of what patients, staff, and family members do depends on a good sound environment: Patients need to sleep and heal without stress; staff, patients, and family members need to communicate accurately but privately; staff need to hear alarms and calls for help.
Concerns about the “soundscape,” or acoustical environment, in hospitals aren't new. We use the term “soundscape” rather than “noise” because a good acoustical environment does not simply reduce unwanted noise; it also provides pleasing or distracting sounds, allows good speech discrimination, allows auditory privacy, supports music as needed, etc. Additionally, soundscape is an immersive concept. That is, it is not just specific sounds that are considered, but also how sound transmits and propagates through spaces, etc. So why aren't all hospitals designed with acoustics in mind? In this article, we will highlight what has been done, what we still need to know, and what you can do about hospital acoustics.
A problematic soundscape
Numerous articles have been written that express concerns over the loudness and chaos of background noise in hospitals. There is also evidence to suggest that a poor acoustic environment in hospitals can be related to negative psychological and physiological reactions in patients and staff.1-3 For example, patients may experience reduced sleep,4-7 a cardiovascular response,8,9 an extended hospital stay,10 and the need for increased pain medication11 due to the loudness of the sound environment. Staff have also shown negative reactions to noise such as burnout,12 stress symptoms,2,13,14 and hearing loss,15,16 as well as decreased mental efficiency,17 decreased short-term memory,17 and difficulties discerning what others are saying.1
Other studies suggest that improvements to the sound environment, such as adding sound-absorbing materials, correlate with improvement in the staff psychosocial environment18 and their perception of noise.19 Additionally, improvements to the sound environment have been related to improved patient sleep20 and decreased incidence of re-hospitalization.21 Obviously, the soundscape should constitute a key consideration in hospital design as the health and safety of occupants is paramount.
Why are soundscapes so poor in most healthcare facilities?
So why are sound environments in healthcare settings often so poor? In part, this is because there are so many noise sources in healthcare settings and because surfaces are typically hard and impervious to allow cleaning. In part, this is also due to the extreme adaptability of healthcare providers. They have worked so long in noisy, stressful, and potentially dangerous settings that they don't know that a quiet, calm, and effective setting is even possible.
In addition, the sound environment is seldom a focus of the design process. If acousticians are involved in the healthcare design process at all, it is typically to reduce HVAC noise; they are seldom asked how to improve sleep, speech privacy, or the ability to communicate accurately or hear alarms. And healthcare acoustics is a new area of specialization; an acoustician with experience in concert halls or airports may not know the special requirements of healthcare.
More fundamentally, a solution to a poor soundscape typically requires the kind of systemic solution that is difficult for most hospitals to achieve. It requires attention to reducing or enclosing noise sources such as HVAC systems, pumps, and wheels on carts; changing communication systems to reduce overhead paging and unnecessary alarms; and talking more quietly. These can all be supported by an improved physical setting with selective use of sound-absorbing ceiling tiles, carpeting, and other sound-dampening materials.
Further research is needed about how to measure the soundscape to best serve patients, families, and staff
Improving a soundscape is made more difficult because, even though we know that the soundscape is problematic, we still don't have a good handle on what specific sources and attributes of the acoustic environment are the worst offenders and, therefore, how best to quantify and improve the soundscape. More concrete evidence is needed about the business case to show that putting money into a good acoustical environment will directly benefit the health and well-being of staff and patients, thereby making acoustics more of a design priority and ensuring this discipline is an integral part of the design team. In addition to convincing administrators, this evidence can directly facilitate an evidence-based design approach.
Together with our collaborators (see acknowledgments below), we are pursuing research in several areas that warrant additional investigation.3, 22 One of the major areas we are examining is linking responses of occupants to specific sound environments. This includes studies with both staff and patients in a variety of hospital units. By relating exact acoustical measures to outcomes, we will be able to better understand what aspects of the sound environment are troublesome to occupants and how to alter these aspects. For example, a previous study with intensive-care unit staff showed that 91% of the nurses surveyed felt that noise negatively affected them in their daily environment, contributing to stress symptoms such as irritation, fatigue, tension headaches, and concentration problems.2 Additional analysis of the sound environment revealed several problematic noise attributes, such as short-term fluctuations.
Another example of our work centers around developing a network measure called “aural connectivity.”22 This measure reflects the overall pattern of where users can hear and respond to different key sounds within a setting. In our studies, we found that nurses in intensive care units must listen for and quickly respond to several categories of key sounds, such as help calls from patients and other caregivers, abnormal bodily sounds from patients, safety-threatening sounds, and alarms. We are now examining how architectural layout, materials, and other design parameters influence the nurses' ability to hear, interpret, and respond to these auditory cues.
What can be done in the interim?
Although there are important remaining questions, designers can begin by acting on current knowledge in their hospital acoustical design. One of the best ways to improve the hospital sound environment is to utilize the services of a building acoustical consultant who is versed in evidence-based design. These consultants rely on concepts in architectural acoustics and engineering noise control to craft a soundscape that is optimum for building occupants. It is important that the consultant work with a multidisciplinary team that can influence care process, culture, and technology: nurses and others who are directly concerned with delivering care and hospital operations and IT staff and others who are concerned with communications and equipment.
There are typically several steps in this kind of collaboration:
Identify and map the tasks that are dependent on the sound environment: meds administration; patient-family-caregiver communication; care team communication; sleep and healing by patients; performance, respite, and recovery by staff, etc.
Assess the current soundscape for these tasks under different conditions, at different times, and different days of the week.
Identify opportunities to control noise or reduce noise sources, add absorbent materials, or other acoustic modifications.
Complete the construction or renovation.
Assess the result and fine-tune as needed.
For example, a project led by Howard Pelton examined the various challenges faced in the acoustical remodeling of an acute care burn unit.23 The focus of the work was the unit's debridement treatment facility, where patients undergo daily removal of dead tissue. This is an extremely painful process, and loud screams from patients presented particular challenges for isolating sounds. In the original facility, it was hard to control noise because it had hard surfaces throughout, privacy curtains only between debridement stations, and inadequate isolation to the rest of the ward. The team mapped tasks, measured and assessed the soundscape, and looked for opportunities to improve it.
They concluded that it was critical to acoustically isolate each debridement station from the others and isolate the debridement facility from the rest of the unit, in addition to adding absorptive materials throughout the debridement facility. This was particularly difficult because the unit needed to be kept absolutely sterile and cleanable, and it was difficult to find commercially available materials that were sound-absorbing yet cleanable. However, the team was able to do an effective renovation that included walls and doors that reduced noise transmission, as well as cleanable absorptive treatments on walls and ceilings that are often used by the food manufacturing industry. Also included were aesthetically pleasing finishes, and headphones and televisions for sound distraction. The result was enhanced privacy and acoustical comfort in the debridement area and the ward.
It may seem obvious to include an acoustical consultant on the hospital design team. Yet, too often they are overlooked or brought in after the design stage-even by experienced hospital designers and administrators. As in other areas of construction, the cost to include acoustics early in the design stage is far less than the costs that would be incurred for acoustical remediation during construction or after the building is completed. Acoustical consultants are critical contributors to the hospital design team that should be included early on-both for new and remodeled facilities.
Conclusions and ongoing work
Our approach is to pursue research that is relevant to the hospital design community and that will impact change in the difficult hospital soundscape. Although designers can act on the things we know now, the results of our research will further bridge the knowledge gap between how hospitals are built and the corresponding occupant response. We are gaining a much better understanding of hospital acoustics and the remaining questions in this area based on the results of the aforementioned research projects and others we are pursuing. Together with our collaborators, we are continuing to investigate the responses of occupants, improvements to our methods of characterizing sound, and targeted design intervention strategies. Based on our findings, we can improve our methods of hospital acoustical design to be more relevant to occupants' needs.
The strong bridges we have formed between architecture, engineering, and medicine are essential to our work. We are extremely grateful for our collaborators, including: Kerstin Persson Waye (Gothenburg University); James West (Johns Hopkins University); Ilene Busch-Vishniac (McMaster University); Selen Okcu and Timothy Hsu (Georgia Institute of Technology); Howard Pelton (Pelton Associates); Melayne Martin (Parkland Hospital); Berit Lindahl, Ingegerd Bergbom and Linda Ljungkvist (Gothenburg University), Jeremy Ackerman, MD, and Owen Samuels, MD (Emory University) and Roger Ulrich (Texas A&M University).
Erica Ryherd, PhD, LEED AP, is a healthcare acoustician, an assistant professor of mechanical engineering and an adjunct assistant professor of architecture at the Georgia Institute of Technology. Craig Zimring, PhD, is a professor of architecture and psychology at the Georgia Institute of Technology and a board member of The Center for Health Design. Both are founding members of the Georgia Tech Healthcare Acoustics Group and are affiliated with the Health Systems Institute, an interdisciplinary initiative based at Georgia Tech and Emory University.
- I. Busch-Vishniac, J. West, C. Barnhill, T. Hunter, D. Orellana, and R. Chivukula “ Noise levels in Johns Hopkins Hospital ,” J. Acoust. Soc. Am. 118, 3629-3645 (2005).
- E. Ryherd, K. Persson Waye, and L. Ljungkvist “Characterizing noise and perceived work environment in a neurological intensive care unit,” J. Acoust. Soc. Am. 123, 747-756 (2008).
- E. Ryherd, J. West, I. Busch-Vishniac, and K. Persson Waye “Evaluating the hospital soundscape,” Acoust. Today 4, 22-29 (2008).
- M. Topf, M. Bookman, and D. Arand “Effects of critical care unit noise on the subjective quality of sleep,” J. Adv. Nurs. 24, 545-551 (1996).
- N. Freedman, J. Gazendam, L. Levan, A. Pack, and R. Schwab “Abnormal sleep/wake cycles and the effect of environmental noise on sleep disruption in the intensive care unit,” Am. J. Resp. Crit. Care Med. 163, 451-457 (2001).
- J. Gabor, A. Cooper, S. Crombach, B. Lee, N. Kadikar, H. Betteger, and P. Hanly “Contribution of the intensive care unit environment to sleep disruption in mechanically ventilated patients and healthy subjects,” Am. J. Resp. Crit. Care Med. 167, 708-715 (2003).
- S. Parthasarathy and M. Tobin “Sleep in the intensive care unit,” Intensive Care Med. 30, 197-206 (2004).
- C. Baker “Discomfort to environmental noise: Heart rate responses of SICU patients,” Crit. Care Nurs. Quarterly 15, 75-90 (1992).
- C. Baker, B. Garvin, C. Kennedy, and B. Polivka “The effect of environmental sound and communication on CCU patients' heart rate and blood pressure,” Res. Nurs. Health 16, 415-421 (1993).
- D. Fife and E. Rappaport “Noise and hospital stay,” Am. J. Public Health 66, 680-681 (1976).
- B. Minkley “A study of noise and its relationship to patient discomfort in the recovery room,” Nurs. Res. 17, 247-250 (1968).
- M. Topf and E. Dillon “Noise-induced stress as a predictor of burnout in critical care nurses,” Heart & Lung 17, 247-250 (1988).
- M. Topf “Noise-induced occupational stress and health in critical care nurses,” Hosp. Topics 66, 30-34 (1988).
- W. Morrison, E. Haas, D. Shaffner, E. Garrett, and J. Fackler “Noise stress and annoyance in a pediatric intensive care unit,” Crit. Care Med. 31, 113-119 (2003).
- Holmes K. Goodman, D. Hang, and V. McCorvey “Noise levels of orthopedic instruments and their potential health risks,” Orthopedics 19, 35-37 (1996).
- K. Willett “ Noise-induced hearing loss in orthopaedic staff ,” J. Bone Joint Surg. Am. OL-73B, 113-115 (1991).
- V. Murthy, S. Malhotra, I. Bala, and M. Raghunathan “Detrimental effects of noise on anaesthetists,” Can. J. Anaesth. 42, 608-611 (1995).
- V. Blomkvist, C. Eriksen, T. Theorell, R. Ulrich, and G. Rasmanis “Acoustics and psychosocial environment in intensive coronary care,” Occup. Environ. Med. 62, 1-8 (2005).
- M. MacLeod, J. Dunn, I. Busch-Vishniac, and J. West “Quieting Weinberg 5C: A case study in hospital noise control,” J. Acoust. Soc. Am. 121, 3501-3508 (2007).
- S. Berg “Impact of reduced reverberation time on sound-induced arousals during sleep,” Sleep 24, 289-292 (2001).
- J. Hagerman, G. Rasmanis, V. Blomkvist, R. Ulrich, C. Eriksen, and T. Theorell “Influence of intensive coronary care acoustics on the quality of care and physiological state of patients,” Int. J. Cardiol. 98, 267-270 (2005).
- S. Okcu, C. Zimring, and E. Ryherd “Descriptors of ‘aural connectivity’: Architectural enclosure features and acoustical qualities,” J. Acoust. Soc. Am. 124, 2463 (A) (2008).
- H. Pelton, E. Ryherd, and M. Martin “Acoustical design of a burn acute care unit for enhanced patient comfort,” Noise Control Eng. J. 57, 32-41 (2009).
Healthcare Design 2010 November;10(11):80-86