A team of researchers led by two University of Maryland Children's Hospital neonatologists is among the first to quantify the benefits of noise reduction on an inpatient unit by moving from a clinical communication system that relies on overhead paging to a mobile smartphone-based system.1

In the hospital setting, background noise has been documented to be a disruptor to sleep and a major source of dissatisfaction for patients and providers alike. Unfortunately, sound levels in hospitals have been increasing for decades. A primary culprit is overhead paging, which accounts for almost 40 percent of disruptive noise on inpatient units. However, in addition to the benefits related to clinical accuracy and efficiency, a smartphone-based hospital communications system can eliminate the need for overhead pages and therefore reduce transitory noises.

To measure the noise reduction benefit of a smartphone-based communications ecosystem, the researchers conducted a pre- and post-intervention study at the University of Maryland Medical Center (UMMC) Labor & Delivery Unit. Led by Colleen A. Hughes Driscoll, MD, assistant professor of Pediatrics at the University of Maryland School of Medicine (UMSOM) and neonatologist at UMMC, and Dina El-Metwally, MB,BCh, PhD, associate professor of Pediatrics at UMSOM and medical director of the Drs. Rouben and Violet Jiji Neonatal Intensive Care Unit, the team's hypothesis was that transitory noise levels would be reduced significantly after adopting a smartphone-based clinical mobility platform.

"Excessive amounts of background noise are associated with adverse effects on well-being, including those on cardiovascular and mental health," says Dr. Hughes Driscoll. "The daytime reduction of noise in a labor and delivery unit is especially relevant since patients caring for a newborn child typically experience disruptions of the day-night sleep cycles and need to sleep at any hour," she continues.

Measuring Noise in the Setting of Overhead Paging

To complete the study, the researchers analyzed nearly 30 hours of sound data collected on the UMMC Labor & Delivery Unit in two distinct epochs within a July 2018 to February 2019 timeframe. They were interested in measuring the number of transitory noises – defined as those less than 10 A-weighted decibels (dBA) above median sound levels – as well as the loudness of those noises. They found that before the mobile-based system intervention, overhead pages occurred at an average rate of 3.17 per hour with attributable sound levels from 49.6 to 76.5 dBA. For comparison, 70 dBA is the approximate sound level of a vacuum cleaner. In fact, 77 percent of all noise louder than 60 dBA and 89 percent of sound levels loud enough to cause annoyance were produced by overhead pages.

Results of Implementing a Smartphone-based Intra-hospital Communications System

After the smartphone-based communications system was implemented, the loudest recorded sound level was 54.3 dBA, a 29 percent decrease from the loudest noise in the overhead paging environment. The researchers also noted that the number of transitory noises was reduced by two-thirds. In the overhead paging setting, 31.2 percent of all hospital sounds exceeded the dBA thresholds recommended by the U.S. Environmental Protection Agency and the International Noise Council. After adopting the smartphone-based system, these excessive noises were reduced to just 0.2 percent. Obviating the need for overhead paging also resulted in a 10 percent decrease of sounds that exceeded the World Health Organization's more stringent standards.

Study Limitations and Future Research Directions

Because researchers collected sound data only during day shifts, it is unknown what, if any, level of noise reduction was achieved by the intervention on night shifts. Sound was measured from empty patient rooms, so noises related to in-room patient care activities were left unrecorded. Also, the two epochs in which sound was measured took place before and after a unit renovation; while the unit had higher patient volumes and was therefore busier in the second epoch with the mobile-based communications platform, the baseline sound levels were also much lower than during the first epoch, suggesting that newer construction materials may have also played a role in mitigating sound.

Despite being measured from a quieter baseline, the smartphone-based communications ecosystem demonstrably helped reduce both the number and loudness of transitory noises during the day. However, more improvement can be made.

"We still have work to do in reducing ambient and transitory noises on our units," says Dr. Hughes Driscoll. "Other technology integrations may be helpful in reducing the noises from essential medical devices and technologies, and turning our attention to these other sources is warranted."

Dr. Hughes Driscoll and Dr. El-Metwally's own unit was designed with sound mitigation in mind. Opening in 2015, the $30-million, state-of-the-art, Level IV Drs. Rouben and Violet Jiji NICU has individual patient rooms, noise absorbent ceiling tiles and wall-mounted noise trackers to help maintain healthy noise levels for neonates.

Learn more about Neonatology at the University of Maryland Children's Hospital.

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1Hughes Driscoll CA, Cleveland M, Gurmu S, Crimmins S, El-Metwally D. Replacing overhead paging to reduce hospital noise. Biomed Instrum and Technol. Jun 2020;54(4):251-257. doi: 10.2345/0899-8205-54.4.251