Johns Hopkins University researchers report that excessive noise in hospitals leads to stressed workers, raises the risk of errors because instructions aren't properly heard, and can even interfere with healing and recovery. The noise from beeping monitors, overhead pages, and ongoing conversations create a tidal wave of sound where everyone speaks more loudly to be heard as the noise level around them increases.
The researchers, Eileen Busch-Vishniac and James West, are acoustics experts. They made 24-hour sound measurements of every area at Johns Hopkins. The facility was consistent with hospitals everywhere, in which average noise levels have risen dramatically since 1960, from 57 dB to 72 dB; evening levels have jumped from 42 dB to 60 dB. In 1995 the World Health Organization issued noise guidelines that put the preferable noise levels in patients' rooms at 35 dB.
Busch-Vishniac and West began at the pediatric ICU. Each bed was surrounded by beeping instruments with intrusive pumps or blasts of warning signals. The sound of doctors and nurses being paged added a noise layer on top of the ongoing conversation among doctors, nurses, patients, families, orderlies and other staff members, with everyone trying to speak louder to be heard. Busch-Vishniac, a professor of mechanical engineering, describes the phenomenon as the "cocktail party effect," where everyone incrementally speaks more loudly to be heard as the noise level around them increases.
West, a professor of electrical and computer engineering, says that this process of gradually talking louder is exhausting for speaker and listener alike. It is draining to be more attentive just to listen to others and is considered one of the reasons that hospital staff suffers from fatigue, he said.
Johns Hopkins is trying several solutions. Instead of acoustical ceiling tiles, which can harbor infectious organisms, fiberglass insulation was wrapped with antibacterial fabric to create sound absorbers, and then attached to ceilings and walls. To lessen pages announced over loudspeakers, staff received small, hands-free personal communicators. The system cut the frequency of overheard pages from one every minute or so to about one an hour.
The simplest solution, however, is low-tech. Busch-Vishniac recommends that people going to hospitals wear earplugs.