In an effort to help make hospitals quieter for patients, an ongoing study at the University of Michigan (UM) Health System‘s hospital is testing sound panels designed to reduce noise.

According to an announcement from the university, a common complaint from patients about hospitals is the noise, which prevents them from sleeping soundly in an environment of alarms and other noises from monitors, paging systems, wheelchairs, gurneys, and carts.

During a noise reduction pilot study, a UM research team strategically positioned acoustic panels in the hospital in an effort to diffuse sound in the hallways around patient rooms. Four custom panels covered in cones made with sound-absorbing material were installed for 3 days in the walls and ceilings of a cardiovascular care unit.

Sound levels were typically 60 decibels during the daytime, according to a study article published in the July 24, 2015 edition of BMJ Quality and Safety, but on hallways with the sound panels, the hospital sound levels dropped to 57 decibels. The study team reports that the 3-4 decibel reduction is recognizable to the human ear and consistent with the sound decibel drop in a car that slows down from 80 mph to 60 mph.

“In hospital environments where noise levels are often double what they should be according to the World Health Organization’s standard decibel guidelines for patient rooms, the difference is significant,” said Mojtaba Navvab, PhD, associate professor of architecture and design at the Taubman College of Architecture and Urban Planning at the University of Michigan.

Navvab and her coauthors, Peter M. Farrehi, MD, and Brahmajee K. Nallamothu, MD, report that the architectural design they are using in the study could complement ongoing strategies for addressing noise in other hospitals. They note that the panels diffuse sound without attempting to eliminate sounds generated by hospital equipment.

According to the UM announcement, research shows that a noisy hospital environment can negatively impact patient health by spiking blood pressure and interfere with wound healing and pain management. Noise also affects hospital staff, as shown by studies that have found a direct correlation between sound decibel levels in work environments and employee blood pressure levels and heart rates.

For more information on the study, read the University of Michigan’s announcement.