The Healing Power of Silence?

Announcements blare from overhead speakers. Electronic devices beep. Heating and cooling systems rumble. Employees and visitors speak loudly.

This sound snapshot, researchers say, comes not from a factory or a sports stadium but from a typical hospital. In a new study, Johns Hopkins University acoustical engineers found that hospital noise levels, internationally, have grown steadily over the past 5 decades; disturbing patients and staff members, raising the risk of medical errors, and hindering efforts to modernize hospitals with speech recognition systems. Some studies even indicate that excessive noise can slow the pace of healing and contribute to stress and burnout among hospital workers.

During a 2-year research project, acoustics experts Ilene Busch-Vishniac and James E. West learned that hospital noise is among the top complaints of both patients and hospital staff members, but that little is being done to address the problem. The researchers found that scientific studies of hospital noise were scarce, and that most had been conducted by medical personnel, not acoustical engineers.

"That told us this problem was important enough that the doctors and nurses were willing to step outside their comfort zone to make some noise measurements, even though they didn't always know how to analyze the data correctly," Busch-Vishniac said. "Acoustical engineers needed to get involved, and it was long overdue. We believe that funding is needed to broaden fundamental research in this area."

Added West: "People have been complaining about hospital noise for years, but little has been done about the problem."

In 2003, when Stephanie L. Reel, vice president and chief information officer for Johns Hopkins Medicine, called their attention to noise levels in the pediatric intensive care unit at Johns Hopkins Hospital, Busch-Vishniac and West agreed to investigate. The researchers surveyed the handful of published reports on hospital noise from the past half-century and made their own sound measurements in several patient areas at Johns Hopkins.

The Baltimore hospital, which provided financial and staff support, also allowed Busch-Vishniac and West to test two techniques that helped reduce noise in some patient areas.

What made their work so different from past research was that it partnered the medical professionals and the acoustical engineers, first to characterize the hospital sound environment and then to find ways to lessen the impact of sound.

"This study focused on a very real challenge," Reel said. "A noisy intensive care unit introduces patient, family, and staff dissatisfaction. It has also been reported that noise can contribute to lapses in short-term memory, which could then introduce safety concerns. Ilene and Jim recognized the importance of this issue and worked with us to address the immediate needs of this pediatric intensive care unit. They also gave us terrific recommendations for the new clinical buildings that will be constructed over the next few years."

The researchers believe their findings have important implications for hospitals worldwide. West and Busch-Vishniac presented their conclusions at the annual meeting of the Acoustical Society of America, held recently in Minneapolis. A paper based on their work will appear in an upcoming issue of the Journal of the Acoustical Society of America.