Page 14 - Fall2019

Hospital Soundscapes
The Impact of Hospital Soundscapes on Staff and Patients
Studies of the impact of hospital soundscapes on the staff and patients have been numerous. In what follows, we summarize the key findings.
Impact of Hospital Soundscapes on Staff
The traditional hospital is designed to be staffcentric. Architectural layouts are set to promote the efficient care of patients, and procedures are established with the staff workflow in mind. Thus, a patient in a hospital might be awakened to have their vital signs checked, reawakened to have the room cleaned, and awakened again to be examined by a doctor rather than being awakened once to have all of these operations done simultaneously. It seems reasonable then to begin our discussion of hospital soundscape impacts
by considering the staff.
The most studied group of medical staff in hospitals are the registered nurses (RNs), who are a large portion of the staff and also work in closest contact with patients. Nursing is a difficult occupation, and stress and burnout are serious job issues. Compdata Surveys studied the problem of turnover in healthcare jobs and found that the average turnover in nurses in 2017 was 20.6%, up from 15.6% in 2010. This turn- over rate is second only to that in the hospitality sector and is more than double that found in occupations with similar education requirements (Rosenbaum, 2018). The cost per nurse turnover in a hospital was estimated by Jones (2008) to be $82,000 to $88,000.
Most of the noise studies on nurses consider the noise/ stress nexus. One of the earliest studies was conducted by Morrison et al. (2003), who followed nurses in a pediatric intensive care unit for three hours and measured the cor- tisol levels in their saliva (a known stress indicator) while simultaneously monitoring the sound pressure level. These authors found correlations between sound level and three items: self-assessed annoyance, self-reported stress, and cor- tisol levels. More recently, Ryherd et al. (2008) surveyed 47 nurses in a neurological intensive care unit, finding that 91% reported noise negatively affects them in their daily work environment. Many reported known symptoms of stress: irritation (66%), fatigue (66%), concentration prob- lems (43%), and tension headaches (40%). Applebaum and Fowler (2010) reported that perceived stress was sig- nificantly related to job satisfaction and turnover intention, thus indirectly linking noise to job satisfaction.
Although these studies show noise and stress are correlated for nurses, they don’t demonstrate a causal relationship. Sound levels on hospital units tend to rise when there is increased activity, usually indicating a medically unstable patient. This makes it impossible to know whether the rise in stress is noise induced or activity induced.
In addition to stress studies, there are some studies of hearing loss and task performance impacts from noise in hospitals. Generally, hospital environments are not sufficiently intense to make hearing loss a concern, but operating rooms are an occasional exception to this rule. Kracht et al. (2007) looked at sound levels in typical surgeries at Johns Hopkins Hospi- tal (Baltimore, MD) and classified the peak levels by type of surgery, as shown in Figure 4. They found that neurosurgery and orthopedic operations have peak levels over 100 dB more than 40% of the time, with peaks occasionally exceeding 120 dB. Sound levels in other forms of surgery were significantly less intense, possibly because they don’t rely on use of bone saws and drills.
Operating rooms are often made louder by the music that surgeons play. A review by Vahed and Kabiri (2016) suggests that 62-72% of surgeons play music while they operate. The wisdom of playing music during surgery has been debated for decades, with no clear research conclusions. The impact of noise on task performance in hospitals is not clear, with some studies finding no significant difference between quiet and noisy conditions (Hawksworth et al., 1998; Moorthy et al.,
Figure 4. Fraction of time that the peak noise level (Lpeak) exceeds 90, 95, 100, and 105 dB (unweighted) by category of surgery. Reproduced from Kracht et al., 2007.
14 | Acoustics Today | Fall 2019