Behavior observation of major noise sources in critical care wards.
OBJECTIVE
This study aimed to investigate the behavior patterns of typical noise sources in critical care wards and relate their patterns to health care environment in which the sources adapt themselves in several different forms.


METHODS
An effective observation approach was designed for noise behavior in the critical care environment. Five descriptors have been identified for the behavior observations, namely, interval, frequency, duration, perceived loudness, and location. Both the single-bed and the multiple-bed wards at the selected Critical Care Department were randomly observed for 3 inconsecutive nights, from 11:30 pm to 7:00 am the following morning. The Matlab distribution fitting tool was applied afterward to plot several types of distributions and estimate the corresponding parameters.


RESULTS
The lognormal distribution was considered the most appropriate statistical distribution for noise behaviors in terms of the interval and duration patterns. The turning of patients by staff was closely related to the increasing occurrences of noises. Among the observed noises, talking was identified with the highest frequency, shortest intervals, and the longest durations, followed by monitor alarms. The perceived loudness of talking in the nighttime wards was classified into 3 levels (raised, normal, and low). Most people engaged in verbal communication in the single-bed wards that occurred around the Entrance Zone, whereas talking in the multiple-bed wards was more likely to be situated in the Staff Work Zone. As expected, more occurrences of noises along with longer duration were observed in multiple-bed wards rather than single-bed wards. "Monitor plus ventilator alarms" was the most commonly observed combination of multiple noises.
Faculty of Architecture and Urban Planning, Chongqing University, Chongqing, China; Key Laboratory of New Technology for Construction of Cities in Mountain Area, Ministry of Education, Chongqing University, Chongqing, China; School of Architecture, University of Sheffield, Western Bank, Sheffield, United Kingdom; Departments of Anaesthesia and Critical Care, Sheffield Teaching Hospitals, Northern General Hospital, Sheffield, United Kingdom. Electronic address: yanshencun@hotmail.com.
Hui
H
Xie
Jian
J
Kang
Gary H
GH
Mills
D000162:Acoustics; D006272:Health Facility Environment; D006801:Humans; D009551:Night Care; D009622:Noise / Q000009:adverse effects*; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000209:etiology*; D013997:Time Factors; D006113:United Kingdom
Acoustic environment; Behavior observation; Critical care; Nighttime; Noise source; Statistical distribution fitting