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Relating the hospital sound environment to occupant psychological and physiological response.

Kerstin Persson Waye
Occupational and Environmental Medicine
The Sahlgrenska Academy, Gothenburg University

Erica Ryherd Woodruff School of Mechanical Engineering, Georgia Institute of Technology,
Berit Lindahl and Ingegerd Bergbom. Institute of Health and Caring Sciences
The Sahlgrenska Academy at Gothenburg University.

Paper no 2112 (2pAAc2), To be presented at session AA14; Acoustics and Privacy in Health Care Facilities II. Emerging Research Around the World. Tuesday 1 July 14.20. Room 243.


Hospitals should be conducive to patient recovery and safety as well as employee health and productivity. Our studies show that patients and personnel are exposed to a sound environment that can be characterized by irregularly occurring high sound events from e.g. alarm signals and activities, with little possibilities for restoration in between. This type of sound environment may pose a risk for disrupted concentration, errors and tiredness among the personnel and repeated arousal reactions i.e. increased hear rate, breathing rate, disrupted sleep and hence impaired recovery possibilities for the patients. For the patients however, factors including medication and depth of sedation may play a role.

A series of studies are being conducted by the authors to evaluate these aspects in relation to the modern hospital sound environment in intensive care units (ICU). The figure below shows data from the first study. The sound is measured throughout the night at the patient’s bedside. The equivalent A-weighted sound levels with blue line at the bottom, maximal level with red line and peak level with dotted line.

Figure 1. The sound environment during a typical night at an intensive ward.

As can be seen number of minutes where the equivalent level is below 35 dB L pAeq (WHO recommended L pAeq value for wards) is non-existing. Similarly the recommended maximum value of 40 dB L AFmax is exceeded all through the night and there are very few moments (minutes) which would allow the patient to rest.

The aim of the current study is therefore to evaluate:

The study involves both a quantitative and qualitative approach to assess the sound environment and its effects utilizing collaborations between engineering and medical sciences.

The study is conducted in a general ICU. Stationary measurements are being conducted at the patient and staff members are wearing dosimeters. Each patient is being monitored for 24 hours during their stay in the ICU. During that time, physiological data (heart rate, blood pressure, oxygen saturation, and pulse rate) are collected and compared to various attributes of the background noise. Additionally, evaluations of ICU delirium are being conducted for each patient. This is a condition in which ICU patients may exhibit a variety of negative psychological reactions. The development of ICU delirium increases the complication rates, prolonges the ICU stay and increases the risk of death. To evaluate personnel health and productivity a questionnaire is answered. It can be seen that the prevalence of noise annoyance is high and related to symptoms indicative of excess sound stimulation and to mental fatigue.

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