Unnecessary noise is the most cruel absence of care which can be inflicted either on sick or on well.”
As recently as the 1960s, hospitals were famous for their quiet and serene environment. Noise restrictions were zealously enforced internally by uniformed nurses and externally by street signs around the perimeter declaring “Hospital—Quiet Zone.
Hospitals and especially operating rooms are no longer quiet.1 In 1972, before the introduction of much of the noisy equipment now routinely used during surgical procedures, it was observed that noise levels in operating rooms frequently exceed those of a busy highway.2 The authors labeled noise as the “third pollution” along with air and water pollution. Others have described the noise in critical care areas as equivalent to the cafeteria at noon and only slightly less noisy than in the boiler room.
More recent studies have reaffirmed the escalation of the noisy atmosphere of hospitals and operating rooms. Average noise levels commonly are greater than federal limits for occupational noise exposure and frequently exceed those considered a hazard to health.
Noise levels of this intensity have wide-spread implications for healthcare workers and their patients. In the following report, we will examine the common sources and possible consequences of excessive operating room noise and suggest some remedies.
Materials and Methods
A literature search was conducted during the period from October 2013 to January 2014 searching for the following terms: noise, noise pollution, occupational noise, auditory perception, hospital, operating room, and music. Searches were conducted using PubMed, Ovid, and Google Scholar. The reference lists of all articles discovered in these searches were examined for additional references.
Regulation of Occupational Noise
Several federal agencies, including the Occupational Safety and Health Administration, National Institute for Occupational Safety and Health, and the Environmental Protection Agency, have developed guidelines and recommendations for safe levels of noise in the workplace. These differ considerably in large part because of differences in the formulae used to determine harmful exposure. For example, the guidelines from the National Institute for Occupational Safety and Health are most conservative in that they begin with a time-weighted average of 85 decibels (A) (dBA) (the allowable continuous exposure for an 8-h work day) and use a 3-dBA time/intensity exchange rate in which the permissible time of exposure is halved for each 3 dBA increase in sound (the “3 dBA rule”)* (fig. 1).The limits established by the Occupational Safety and Health Administration begin at 90 dBA for an 8-h work day and use a 5-dBA exchange rate in recognition of the fact that in most workplaces interruptions in noise exposure occur throughout the day.† Specifically within hospitals, average noise levels of 45 dBA or less are recommended. Both National Institute for Occupational Safety and Health and Occupational Safety and Health Administration guidelines agree that the peak level for impulsive noise (characterized by a steep rise in the sound level to a high peak followed by a rapid decay) should not exceed 140 dBA.