Quiet times, soundscapes improve outcomes in NICUs

Jonathan Weber, PhD

A quiet, calm atmosphere can have positive effects on neonatal outcomes, and neonatal intensive care units (NICUs) can set the tone for creating these environments, according to a new report.

In one of the first studies linking a quiet environment to neonatal health, the research team examined the effects of quiet time interventions in multiple NICUs. Following the study cohort for up to 18 months after implementation, the research team found that quiet time protocols in NICUs may help improve infant health outcomes.¹ The research team presented its findings at the 177th Meeting of the Acoustical Society of America held in Louisville, Kentucky, in May 2019.

“NICU noise literature consistently shows high ambient NICU noise levels that exceed currently recommended levels. Knowing that noise can have negative impacts on humans in general, it is unsurprising that literature often supports similar claims in hospitals,” says Jonathan Weber, PhD, who served as lead graduate assistant on the project and is now a postdoctoral research associate at the University of Nebraska-Lincoln, Omaha, Nebraska.

“Whereas some noise is driven by the built environment and unit design, general unit operations can also be a large contributor to the noise environment or soundscape,” Weber says. “It is important to raise awareness within hospital units and simply be conscientious of unnecessary contributions to the soundscape to help provide a more relaxing and healing-conducive environment.”

Focus on patient environments

The healthcare industry is in a state of transition, according to the researchers, moving from a focus on survival alone to one of patient care with the expectation of survival as a result. Because of this trend, they set out to identify the optimal hospital environment. Focusing on intensive care units (ICUs), which are often noisier due to the urgent level of care provided, the research team investigated the effects of quiet-time interventions from both the acoustic and medical perspectives. Both acoustic and physiologic patient measurements were taken to explore the relationship between quiet-time interventions and infant health, and how soundscapes could be used to improve overall health.

The team worked with nursing staff in several NICUs to develop structured quiet-time guidelines, which included limiting conversations during certain hours, dimming lights, and coordinating housekeeping and other services to limit activity during certain afternoon and night hours. Lights dimmed, and lullabies were played to signal the start of quiet time, according to the report, and nonessential activities that may cause noise were rescheduled for other times. The team also studied how the units in the study were designed, and how the layout, building materials, and even heating/ventilation/air-conditioning systems may contribute to noise levels and sound control. The team then measured how the NICU soundscape changed throughout the day and what effect it had on the infants.

The infants in the study seemed to thrive during quiet times, according to the data, helping them transition to life outside the womb and reducing stress. Specifically, infants had improved heart rates during quiet times, and noise directly correlated to negative physiologic responses from the infants.

An important message

It is difficult to tease out which interventions helped the most in the quiet-time hours, Weber adds, because all the interventions were implemented at once and were not individually tested. Still, he says, the overall message is clear.

“Considering all the layers of analysis, we found that raised noise levels, transient noises, and noise fluctuation were all inversely related to infant heart rate. Therefore, interventions that reduce overall noise levels, reduce the frequency at which loud noises occur, and reduce the overall noise fluctuation could potentially help improve infant outcomes,” he says.

Some examples of the protocol used in the study included behavioral modifications such as reduced conversations and relocating conversations away from patient bedsides; environmental modifications as reduced lighting and silenced cell phones; and scheduling modifications, such as no routine cleaning or medical procedures, and limited visitation.”

It wasn’t so much the decrease in overall loudness-which didn’t drop as much as the team had hoped-that helped the most, according to the study, but other key areas. Specifically, the report reveals that loud sounds occurred less frequently after the quiet-time interventions were instituted, more time was spent in quiet time with quiet periods becoming longer and more frequent, and the pitches of ambient noise and other sounds in the NICU were reduced.

Implementing quiet time can be a burden to staff and often require a habituation period to adjust to behavioral and scheduling changes, Weber says, but the research team found that staff typically perceived quiet time very positively. Additionally, whereas quiet times helped, Weber says intervention should not stop there.

“This project demonstrated some improved outcomes-both infant health and noise-by evaluating operational changes. However, it is stressed that the infant outcomes were only collected and assessed for 1 of the 3 hospitals studied in this project,” Weber says. “Although quiet time did reveal some potential benefits, we recommend it be coupled with additional engineering or architectural solutions, which can help provide more permanent and consistent soundscapes.”

A step further

The researchers revealed that while improvement in infant outcomes in NICUs is a goal, they hope their research extends to impacting noise levels in other areas of patient care in the hospital as well.

“We hope that this work will continue to raise awareness of the importance of good soundscapes for patient health. We also understand that this work of quiet time can easily be expanded as it is not limited to any single unit type. Quiet time could be implemented in other sites such as NICUs with different layouts or care models as well as pediatric and adult units,” Weber says. “I think additional research and collected data can help us better understand the specific noise characteristics that may be harmful and those that may be beneficial to different patient populations. This information could then help us better address specific interventions and unit designs to help create healthier hospital soundscapes.”

References:

1. Weber JR, Ryherd EE, Mahoney AD. Quiet time impacts on the neonatal intensive care unit soundscape and patient outcomes. J Acoust Soc Am. 2019;145(3):1657.