Hospitals are too darn noisy for a patient's own good. Just ask Dr. Roger S. Ulrich, professor of architecture and director of the Center for Health Systems and Design at Texas A&M University, College Station. Ulrich recently spent about six months researching evidence-based design for the Center for Health Design. He's analyzed a small mountain of scientific studies focused on noise and patient outcomes, and he has proof that patients and staff do better in quiet settings.

At hospitals that cut noise levels, Ulrich found, patients slept better, had lower blood pressure, were less likely to be rehospitalized and were more satisfied with their care. Similarly, staff reported improved sleep quality and felt better about their jobs.

Noise has plagued hospitals for decades. Exactly how bad is the problem?

"Virtually no hospital meets guidelines or recommended standards for either continuous noise levels or peaks, whether at daytime or nighttime conditions," says Ulrich. "The World Health Organization recommends that continuous background noise in hospital rooms should not exceed 35 decibels (dB), and nighttime peaks in patient care areas should not exceed 40 dB. But many studies have found that background noise levels typically are in the range of 45 to 68 dB and many peaks commonly exceed 85 or 90 dB."

A portable X-ray machine typically measures in at 90 dB, says Ulrich. Many alarms are in the range of 85 to 90 dB. Paging systems range from 75 to 80 dB. A nursing team studying noise levels at the Mayo Clinic-affiliated Saint Mary's Hospital in Rochester, Minn., measured a nighttime peak of 113 dB during a shift change in a large surgical care unit.

To put these numbers in perspective, every 10 dB increase seems twice as loud to the human ear.

'Far, far less noisy'

If Ulrich had his way, hospitals would build only private rooms. "The intervention of greatest importance from the standpoint of reducing noise sources and improving acoustics is to create single-patient rooms," he says. "It is very clear in the scientific literature that single-bed rooms are on average far, far less noisy. These studies clearly show that the sources of noise in double rooms are overwhelmingly associated with the other roommate."

Referring to data collected by Press Ganey Associates, South Bend, Ind., which processes satisfaction surveys for thousands of health care facilities throughout the United States, Ulrich says, "There is an overall difference for people in single-occupancy rooms to be 11 or 12 percentage points higher in their satisfaction with acoustics or noise level. That's an enormous difference, considering that it can be very difficult for hospitals to achieve even a 1 or 2 percent increase in satisfaction.

"Noises are far less numerous and they're under the control of the patient in a single-occupancy room," he continues. "You get better acoustics because the environmental intervention can be to close the door and have hard walls around you as opposed to cloth partitions which have no sound attenuating value. Plus, you get many noise sources removed. It's a huge win as an intervention."

Worst-case acoustics

Ulrich insists that much of the noise in hospitals is unnecessary. There are too many noise sources, he says, and they're too loud. Compounding the problem is the fact that hospitals often have worst-case acoustical conditions. All those gypsum board ceilings and other hard surfaces are highly cleanable, but they don't absorb sound. Instead, they amplify and reflect sound, sending it traveling over longer distances and impacting patients and staff over larger areas. Thus, high-performance acoustical ceiling tile can dramatically reduce noise levels.

When selecting tile, facilities professionals should consider the product's Noise Reduction Coefficient (NRC), which indicates the product's ability to absorb sound. They also should consider the tile's Ceiling Attenuation Class (CAC), which indicates the product's ability to block sound. The higher the numbers, the better. Jonathan Leonard, vice president, Lencore Acoustics, Merrick, N.Y., recommends acoustical tile with an NRC above .85 and a CAC of at least 35.

Susan Gibson, vice president for mission services, Saint Alphonsus Regional Medical Center, Boise, Idaho, can attest to the effectiveness of high-performance acoustical ceiling tile in patient rooms. To meet an immediate need for 40 beds while waiting to build a new acute care tower, Saint Alphonsus transformed an old office floor into a general medical care unit. Renovation gave the hospital an opportunity to test a new design methodology that included all private rooms with acoustical ceiling tile.

When all was said and done, Saint Alphonsus found a significant difference in noise levels between unoccupied new and old rooms. "We measured the amount of time that the decibel level was under 51.7," says Gibson. "There was far more time that it was under 51.7 in the renovated rooms."

The new ceilings impressed patients too. In satisfaction surveys using a 10-point scale, patients rated their quality of sleep at 7.3 in the new private rooms versus 4.9 in the old semiprivate rooms occupied by a single patient. "Many studies show that quality of sleep is a variable in patient recovery," notes Gibson.

St. Charles Medical Center in Bend, Ore., is expanding its patient tower and also plans to install acoustical ceiling tile in the new rooms. "In order to meet code in the past, patient rooms had to have a hard-lid ceiling," explains Jerry Gardner, the hospital's director of facility development. "That has been relaxed, and you can now have acoustical ceilings."

Warmer, quieter environment

In an effort to create a warmer, quieter environment, St. Charles Medical Center has also been laying sound-absorbing carpet in patient rooms and hallways for the past 30 years. Contrary to popular belief, keeping the carpet clean hasn't been a problem. "Early on, we did infection control testing," says Gardner. "We found that we did not grow anything in carpet that we wouldn't pick up from a hard-surface floor. In some cases, we picked up fewer items."

St. Charles has standardized on commercial grade carpet glued directly to the concrete floor. "There are no pads below the carpet, so we can easily roll over it with carts, beds and stretchers," notes Gardner.

A sound masking system adds ambient background sound into spaces and can be a highly effective solution for creating quiet amidst hard surfaces.

"By raising the ambient background sound level, we put you at a place like the beach, which most people find to be very relaxing," Leonard explains. "One of the reasons all the different activities that occur at a beach aren't distracting to people is because there's a high level of pleasant ambient sound coming off the ocean, and that ocean sound is louder than most of the other sounds that are trying to come in. You have a very small dynamic range and the spikes (noise from other activities) become either nonexistent because they occur underneath the higher ambient background sound level of the ocean, or they're so small that they're only slightly louder than the ambient sound of the ocean. And so, by introducing sound or gently raising the ambient background sound of a space, you give an environment that quietness that most people desire."

Sound masking solved acoustical problems at Holy Spirit Hospital's new 140,000-square-foot Ortenzio Heart Center in Camp Hill, Pa., where nurses' stations are open and patient rooms have hard ceilings. "We used hard ceilings in patient rooms thinking that it would be easier to clean those ceilings than tile," says Tim DeBlaey, vice president for cardiovascular services. "Of course, that put us into a quandary about why patient rooms sounded like echo chambers."

Holy Spirit Hospital opted for sound masking when they discovered the cost of installing it in patient rooms, waiting areas and at nurses' stations, reception desks and transaction counters was less than the cost to carpet the nurses' stations alone.

"The sound masking system did everything for us," says DeBlaey. "From a HIPAA (Health Insurance Portability and Accountability Act) standpoint, it helped mitigate some of the information-sharing through the airwaves. It also got rid of the echo effect in patient rooms."

Patient volume at Ortenzio Heart Center is twice what it was in the old facility, but noise levels are far more subdued.

"Before, one of the major complaints that came up through our patient survey system was noise level, particularly after hours when things are quiet in the hall with the exception of the nurses' station," says DeBlaey. "Now, if a patient is in a room and people wearing hard-soled shoes walk by, you can't hear their footsteps from inside the room. Several patients have commented about how quiet the heart center is and how well they slept."

A commensurate attempt

Of course, absorbing, muffling, neutralizing or shutting-out unwanted sounds can only get a hospital so far without being matched by a commensurate attempt at stopping noise from being generated in the first place.

Indeed, the most successful noise-reduction strategies combine design and engineering solutions with a team approach that also involves staffing and equipment.

For example, patient satisfaction with noise was just 50 percent at Northside Hospital in Atlanta, Ga., when a continuous quality improvement team was formed to find ways to dial down the volume.

"Our mission was to reduce the noise level in and around patient rooms and common areas to create a more restful and healing environment and to improve customer satisfaction," says June Morrison, director of rehabilitation services. "We focused on noise issues related to staff and things we had control over, such as equipment purchases and continuous equipment repair."

Patient areas are quieter now at Northside thanks to the team's efforts. The hospital eliminated elevator door alarms, padded the pneumatic tube system and replaced overly loud fire alarms with a system that meets code but measures lower on the decibel scale. Fixing or replacing squeaky wheels reduced noise levels of heavy rolling equipment from 80 dB to 49 dB and of smaller equipment from 68 dB to 50 dB.

"We set up a policy that no one could be paged over the loudspeaker system," adds Morrison. "Now, most people that need to be paged are on beepers that vibrate. They are also on a phone system which they can put on vibrate, and they can step into another area to talk.

"Our goal was 10 percent [improvement in patient satisfaction with noise]," says Morrison. "On the average, satisfaction certainly rose."

Such was also the case at the Mayo Clinic-affiliated Saint Mary's Hospital, where the nursing team reduced nighttime noise levels through facilities measures like replacing roll-type paper towel dispensers with folded-towel dispensers and placing foam rubber padding in chart holders and in the pneumatic tube system, along with making staff members aware of the problem, adjusting schedules to minimize noisy activities at night, and lowering volume levels on clinical and communication equipment.

In another example, Bon Secours St. Mary's Hospital in Richmond, Va., reduced the noise of its cleaning and maintenance staffs by utilizing a "Quiet Dolly" product made by Rubbermaid Commercial Products, Winchester, Va., to move equipment.

Furnishings can also be a culprit in unwanted noise cases. "We had an interesting situation in an operating room in a Bay Area hospital," notes Charles Salter, president of acoustical consulting firm Charles M. Salter Associates, San Francisco. "The chief of surgery wrote to the head of the hospital saying, 'Patients are in danger of dying as a result of the acoustics in the operating rooms.'

"Operating rooms are very quiet rooms and have all hard surfaces to provide the most cleanability in terms of germs," Salter continues. "The problem here was that the cabinets where they kept materials had sliding door panels which, when slid open, sounded like a machine gun going off.

"Imagine a doctor hunched over a patient trying to cut an artery very, very carefully, and that sound occurs," he adds. "That level of noise would be enough to cause anybody to jump, whether you're a veteran surgeon or a bus driver. If that cabinet gets opened at just the wrong time, the involuntary movement of the surgeon could kill a patient."

Through cultural change

Susan Mazer, president and CEO, Healing HealthCare Systems, Reno, Nev., helps hospitals reduce noise through cultural change. "We deal with the behavioral part of shifting that environment and then creating an accountability among staff," she says. "If there is a technological or physical answer [to reducing noise], staff are the ones who not only control it but who also make requests for [solutions] and set the standard in maintaining an appropriate environment that supports the therapeutic objectives of patients."

At St. Charles Medical Center, one of Mazer's clients, that translates into raising awareness among staff about things like keeping their voices down in hallways and making sure noisy equipment gets fixed.

At Northside Hospital, another Mazer client, it also translated into Morrison's team making posters and stickers that read, "Quiet please, healing in progress." The team placed the posters and stickers throughout the hospital to remind staff and visitors to keep their voices down.

However, just as noise can be detrimental to patient outcomes, a too-quiet environment can have an adverse effect. "When patients are in rooms that have visual barriers, their access to what's going on is limited to the doorway," says Mazer. "The other information that comes to them, that lets them know there are activities outside the door, is auditory. Patients would be unnerved if they heard nothing. They want to know people are there doing their jobs."

And some sounds promote healing and satisfaction. An audio system that plays instrumental music, for example. "In hospital settings, music combined with images of nature have been shown to reduce the amount of requested pain medication and/or improve its analgesic effect," wrote Mazer in a July 2002 article for HFM (see sidebar, this page). "In addition, when used appropriately, music acts as an effective audio-anxiolytic, improving restfulness and the quality of sleep and inducing relaxation."

Northside Hospital periodically invites harpists and other local musicians to come in and play quietly in an area near patient rooms. "We've had patients say they turned off their TV just so they could hear the harp in the hallway, and that it was very soothing for them," says Morrison.

Seriousness of the problem

"Noise research has been getting better in recent years," says Ulrich. "More work is being done by people who are rigorous scientists and using new types of highly sensitive medical measures. As a result of that, I would conclude that noise is a greater problem than previously recognized in terms of having negative effects.

"The emerging conclusion," Ulrich adds, "is that the amount of noise needed to have negative effects on important outcomes is considerably less than previously thought. This underscores the seriousness of the noise problem and the need to get these noise levels down. And, it is doable."

Dana Dubbs is an Escondido, Calif.-based freelance writer who specializes in design issues.

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