A remedy for hospital noise

Noted acoustics expert works on turning down the volume at Johns Hopkins

September 09, 2007|By Dennis O'Brien | Dennis O'Brien,Sun reporter

Tour a hospital with James West and you begin to notice something - it's a noisy place.

Alarms on patient monitors are always beeping. When supply and cleaning carts clatter by, staff and patients have to raise their voices to be heard. Overhead paging systems and chirping telephones create a cacophony that makes it hard to work - and harder to heal.

The 76-year-old West is trying to change that. The solutions can be as simple as replacing noisy public address systems with silent pagers, or as complex as finding new materials to absorb noise without risking patient safety.

As an acoustics professor at the Johns Hopkins University, he knows something about these issues - in fact, he was co-inventor of the electret microphones that millions of us use every day in our telephones and tape recorders. He joined the Hopkins faculty in 2002 after four decades developing audio technology at Bell Labs New Jersey - a career that this summer brought him the nation's highest honor in his field, the National Medal of Technology.

"He was a terrific catch for Hopkins," said Ilene Busch-Vishniac, who worked with West at Bell Labs in the 1980s and recruited him when she was the school's dean of engineering.

Even so, making hospitals quieter is an uphill battle. Experts say hospitals are designed to provide patients with effective and efficient care. But they also present obstacles to fighting noise.

For example, the ubiquitous sound-absorbing carpets and acoustic ceiling tiles in many workplaces are prohibited in hospitals because they harbor bacteria and are hard to clean.

The result is an environment with tiled floors, paneled walls and bare ceilings that reflect sound the way mirrors reflect light, West says. Together, they create a series of echo chambers.

"All these units have always been noisy, and we know why," said Anita Reedy, nurse manager of an oncology unit at Johns Hopkins Hospital. "We can't have carpets and acoustic ceilings because we have immuno-compromised patients."

When he walked into Reedy's unit in the Weinberg Building last week, West focused immediately on the floor plan: Its four corridors connect at right angles. That means sound travels the hallways without barriers, and conversations at one end of a hall can be heard at the other.

Recessed areas in the ceiling above the nurses' station, where two hallways intersect, also amplify ringing telephones - and any conversations.

"It's really not the best design in terms of sound," West said. So he's looking for a material he can use to develop hygienic and affordable fiberglass soundproofing panels for Hopkins and other hospitals.

Recordings of voices and other everyday sounds on Reedy's unit show that the custom panels that West's team attached to the ceilings in 2005 cut noise levels in half. West plans to present those results to the Acoustical Society of America next month.

Unfortunately, those panels cost about $15,000 to install - too expensive for installation at Hopkins and other hospitals. "To make this work, we have to find something affordable," he said.

West has been solving acoustical problems since his days as an intern at Bell Labs in 1957, when he was majoring in physics at Temple University in Philadelphia.

Over the years, he has studied the way sound travels - whether it's through the confines of electrical wiring or inside the world's great concert halls, including Lincoln Center's Avery Fisher Hall, Carnegie Hall and the Academy of Music in Philadelphia. Workmen closed gaps in ceiling panels in Avery Fisher Hall years ago after West and his colleagues discovered they were causing acoustical problems.

Individually or jointly, West holds more than 40 U.S. and 200 foreign patents. At Bell Labs, he and Gerhard Sessler invented the electret microphone, a tiny device made from thin sheets of polymer that makes voices easier to hear.

The electret is used in over 90 percent of the world's telephones, camcorders and other recording devices, a success that earned West a place in the National Inventors Hall of Fame in Akron, Ohio.

"I think he's one of the top people in the field of acoustics," said Sessler, on the faculty of Darmstadt University of Technology in Germany. The Bell laboratories where they worked are now part of the Paris-based Alcatel-Lucent communications giant.

West's noise reduction efforts at Hopkins began about three years ago, when hospital officials asked him and former engineering dean Busch-Vishniac to examine the pediatric intensive care unit.

"This can be a real noisy place," said Claire Beers, the unit's nurse manager. Each child is connected to monitors that sound alarms if there are problems with vital signs, including blood pressure and heart rate levels, Beers said. Many of the unit's patients also are hooked up to ventilators and up to six different infusion pumps.

"And all of them have alarms," Beers said.

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