Each time the average noise exposure increased by 10 decibels, systolic blood pressure crept up an average of 2 millimeters of mercury -- which is how blood pressure is measured. When the noise increased by 13 decibels, diastolic blood pressure also rose by an average of 2 millimeters.
The European study involved all 32 hospitals in Berlin between 1998 and 2001 and was designed to look at the association between the annoyance that chronic noise triggers in people and its effect on heart attacks in men and women.
When the body experiences annoyance, a whole set of physiological changes occur, such as increased levels of adrenaline and noradrenaline, which are associated with increased blood pressure and inflammatory responses that are implicated in heart disease and heart attacks. If noise triggers those responses, then it could be considered a real risk factor for cardiac problems.
The team found that the general noise in the environment, like traffic or airplanes, affected both genders and increased the overall risk of a heart attack by nearly 50% for men and 75% for women.
Then there was workplace din, which was a problem for men, increasing their risk by nearly a third, but which did not seem to affect women.
Quieter halls
The Johns Hopkins researchers came up with two sophisticated solutions to the hospital problem. They found that the hospital did not have acoustical ceiling tiles, which can harbor infectious organisms, becoming in effect acoustical petri dishes. But the researchers came up with a substitute: By wrapping fiberglass insulation inside an antibacterial fabric, they created sound absorbers, which they then attached to the ceiling and walls of an oncology unit, muffling some of the sounds that used to bounce freely in the area.
To lessen the blasts from the pages announced over loudspeakers, the pediatric ICU staff was given 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, may be decidedly low-tech -- one that even Florence Nightingale could have prescribed.
If you go to the hospital, says Busch-Vishniac, "I would strongly recommend wearing earplugs."
