Sound Benefits
Keeping noise down in NICUs goes a long way in improving babies’ health.
By Scott Williams
January 17, 2005
Babies are known for their ability to make noise. Nature designed their ear-piercing and often heart-rending cries to be impossible to ignore. It’s ironic, therefore, that newborns — especially premature and critically ill babies — suffer when exposed to excessive noise.
A number of studies during the past three decades have repeatedly shown that newborns suffer a range of physical, emotional, and developmental problems when exposed to excessive noise. These findings have led hospitals across the country to reduce noise levels in their neonatal intensive care units by modifying hospital designs, operational policies, and human behavior.
Measurements of noise levels in NICUs dating back to the 1970s found routine sound levels ranging from 70 decibels to as high as 117 decibels; normal conversation usually measures about 60 decibels. For the protection of public health, the U.S. Environmental Protection Agency has proposed a day-night average sound level (DNL) in hospitals of 45 decibels in the daytime and 35 decibels at night.
What’s at stake
One of the earliest studies conducted on the effect of noise on neonates, which was published in 1980, found that noise and frequent disturbances by nurses and physicians may cause hypoxemia in sleeping babies. Other studies indicate that newborns who are exposed to high levels of noise suffer from hearing loss, stress, psychological changes, and habituation problems. Different studies show that newborns benefit from a “quiet hour” and from wearing specially designed earmuffs.
Cindy Harmon, RN, NICU nurse manager for Wesley Medical Center in Wichita, Kan., says reducing noise was one of the primary considerations when the hospital designed and built a new unit in the early 1990s. The previous NICU was a long room that did little to reduce noise. A person at one end of the room could hear someone talking at the other end, says Harmon, who adds that the new unit took some getting used to.
“When we moved in, we could hear the air flow of the ventilators because it was so quiet,” she says.
The babies didn’t complain, and neither did the parents, who often were shocked when they walked into the hospital’s old NICU. “It was hard for parents to walk into that kind of a setting, especially for the first time, and be inundated with the noise,” Harmon says.
Noises off
Harmon says newborns, and especially ill and low-birthweight babies, need every calorie they get to heal and grow. She says dealing with the fear and stress caused by excessive noise robs them of some of those calories. Taking measures to reduce noise, and therefore increase sleep, helps these babies develop their brains.
“The brain is developing, especially in a premature baby, during that period of time in ICU,” Harmon says. “So keeping things within a normal or expected range is going to reduce potential problems or concerns with that brain development.”
Lisa Logan, RNC, assistant nurse manager at Cox Health South in Springfield, Mo., says her facility’s 52-bed NICU follows the recommendations set forth in the Neonatal Individualized Developmental Care Assessment Program, which was developed by Heidelise Als, PhD, of Children’s Hospital Boston. NIDCAP includes measures for reducing noise in NICUs.
“Part of [the program] is developmentally calming the babies [and] bundling the babies,” says Logan, who has been a nurse for 22 years. “All those factors together help to promote growth and development and help decrease their stays here.”
At Cox Health South, the NICU is divided into sections with “quiet please” signs over each doorway. A monitor tracks the unit’s noise level, and a light flashes when the level exceeds the recommended number of decibels. Earmuffs are even used in some instances to protect precious ears. The smallest babies — those in the 1- to 2-pound range — are kept in high-tech “duress beds” that can be closed to keep the baby warm and insulated from noise.
And Logan says you won’t find nurses yelling across the room to each other, either.
“As a general rule, over the years the nurses have learned in their own conversations to speak quieter,” she says.
Logan adds that nurses and the health care team at Cox also limit visitation to keep the unit from becoming overcrowded with noisy people. They have also turned off telephone ringers, removed lids from trash cans, and adjusted the hospital’s intercom system to receive fewer pages and at a lower noise level. Radios are not allowed in the unit, and nurses respond to beeping alarms as quickly as possible. Alarms, she says, are a Catch-22. “You’ve got to have them loud enough so you can hear them, but we don’t have them as loud as they can be.”
All this effort to reduce noise might make you think all noise is bad, but Logan says that isn’t so. Some noises have a calming effect on babies and are encouraged in the NICU. At Cox, nurses use noise machines that simulate a mother’s heartbeat or emit bird or wave sounds to drown out other noises and soothe the babies. Some mothers make recordings of themselves reading, singing, or talking with their other children. Logan says the tape is then placed in a tape player and played softly to comfort the baby.
Shhh, babies
Logan says one of the most difficult challenges is limiting the noise the babies themselves make. Some aren’t allowed to eat, and many have physical problems that cause discomfort and pain. “It’s a constant battle to keep them calm and quiet so they donupset the other babies,” Logan says.
Cox’s NICU divides the babies into rows that, in the past, were separated by filing cabinets with space between the cabinets and ceiling. That allowed noise from one row to travel over the cabinets to another row. A redesign eliminated the gap, and the next time the NICU is remodeled, which Logan says could be in five to 10 years, the design will allow them to isolate babies from one another.
Harmon says spreading out the babies was one of the goals when Wesley Medical Center designed its new unit. She said they also installed carpeting, acoustical tile ceilings, and sound-absorption materials in walls and altered ceiling heights to make it harder for sound to travel. The carpeting was later removed because keeping it clean became difficult and required the use of loud machinery.
“We put some areas in the ceiling that helped to prevent the bouncing of noise around the room,” Harmon says. “The noise level is less and people are more aware of the need to keep voices low.”
Telephones in the unit have a light connected to them that blink when someone calls, and most personal pagers are set to vibrate or emit a single beep. Overhead paging is limited to the hallways, and Harmon says ventilators are much quieter than in the past.
Harmon says parents are quick to buy in to the desire to reduce noise.
“Parents are usually pretty good about helping once they understand what it is we are trying to do,” she says. “They say, ‘It’s starting to get noisy’ or ‘My baby does not like that noise.’”
Sue Ehelebe, RN, patient advocate at Lake Regional Hospital in Osage Beach, Mo., says noise isn’t just a problem in NICUs. A patient survey at her facility discovered patients found the hospital noisier than they would have liked.
A customer service team of hospital employees worked on a way of reducing the number of carts that are wheeled through the halls and looked for routes that did not pass by patient rooms. They also came up with a fun way to remind employees to be quiet. A member of the maintenance staff, who also happens to be an excellent photographer, took photos of employees’ children wearing nurse and physician uniforms and putting a finger up to their lips.
“We found signs saying ‘Quiet Please’ or whatever related to noise just didn’t seem to be as workable,” Ehelebe says. “Everybody has really enjoyed it and it has certainly helped our noise level.”
Scott Williams is a freelance writer.