Page 23 - Fall 2008

EVALUATING THE HOSPITAL SOUNDSCAPE
Erica E. Ryherd
Mechanical Engineering, Georgia Institute of Technology Atlanta, Georgia 30332
James E. West
Electrical & Computer, Mechancal Engineering, Johns Hopkins University Baltimore, Maryland 21218
Ilene J. Busch-Vishniac
Provost and VP Academic, McMaster University Hamilton, Ontario, Canada L8S 4K1
Kerstin Persson Waye
Occupational and Environmental Medicine, Gothenburg University 405 30 Gothenburg, Sweden
Environments where decisions are made affecting health and survival and where patients reside should promote thinking, communication, good patient care and restfulness for the patients. It may seem a strange principle to enunciate as the very first require- ment in a hospital that it should do the
1
sick no harm. However, the complex
hospital auditory environment or “soundscape” has long been a key source of complaints among hospital
2,3
staff, patients, and visitors. Hospitals are dense with
ambulatory people who rely heavily on oral communication and therefore the hospital soundscape is densely populated by speech. There are also a variety of mechanical noise sources such as beeping alarms, medical respirators, over- head paging systems, floor cleaners, and air-conditioning systems. Couple speech and mechanical noises with patient distress sounds and activity noise from busy staff in a high- ly reverberant space, the result is a dynamic soundscape that is far from restful and can make understanding speech difficult. This article summarizes what is known about the hospital soundscape and its impacts and describes ongoing work for improvement.
Effects of hospital soundscapes on occupants
Concerns about the hospital soundscape aren’t new— researchers have been looking at ways to quantify this unique auditory environment and its effects for several years. Of par- ticular interest are the negative health impacts of the hospital soundscape on patients, staff, and visitors. Ideally, hospitals should be conducive to patient recovery and safety, employee health and productivity, and visitor comfort. However, research suggests that a host of negative symptoms may be partially or primarily attributed to the hospital sound envi- ronment and warrant detailed investigation.
It is well-known that noise can have both psychological
4,5
Previous research on hospital patients have documented negative impacts such as a reduction in the recuperative properties of sleep, including
and physiological effects on humans.
depth, continuity, and duration.
6-9
Effects such as cardiovas-
Ultimately, we hope that our research facilitates change in the hospital soundscape— creating a safer, healthier environment for patients, staff, and visitors.
cular arousal,10-11 extended hospital stay,12 and increased dosages of pain medica- tion13 due to excessive noise levels have also been documented in patient studies. Decreased healing is another potential concern as a few studies on animals have revealed that noise exposure may slow
14,15
Speech interfer- ence and increased medical errors are two additional poten- tially hazardous effects of hospital noise that could have obvi-
2,18
Furthermore, increased sound absorption that tends to make speech more intelligible and lower back- ground noise levels has been linked to improved sleep in an experimental study,16 a reduction in cardiovascular arousals,17 and
17
wound healing.
decreased incidence of re-hospitalization.
Indeed, there is a growing body of research on pharmaceutical name recog-
ous negative implications for patient safety.
nition in noise similar to that found in hospitals.
The impact of the hospital soundscape on staff members is also a concern. Statistics indicate that 14 million people are employed in the U.S. healthcare industry, with 4.9 million of
19
them working specifically in hospitals.
Therefore, the qual-
ity of this occupational environment affects a large segment
of the population. There is some evidence that overall levels
of hospital noise may contribute to stress20-23 and burnout,24 a
serious concern given the current nursing shortage through-
out the U.S. Other studies suggest that the acoustical envi-
ronment contributes to decreased short-term memory,25
decreased mental efficiency,25 and decreased ability to aurally
distinguish critical physiological functions such as heart and
26
lung sounds. Some studies indicate that orthopedic staff
27,28
The consensus from previous work is that the hospital soundscape is problematic and that it is becoming worse, even in new construction. Recent research shows that hospi-
Increased sound absorption has been shown to correlate with improve- ment in the staff psychosocial environment29 and improved perception of the soundscape (i.e., increased satisfaction with
30
may be at risk for noise-induced hearing loss.
the overall noise level).
Current knowledge
22 Acoustics Today, October 2008