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Study Reveals Decibel Levels Too High at Typical Hospital


CONCORD, CA – Intravenous pump alarms and conversations between nurses are essential to hospital patient care, but they are also highly likely to keep patients from getting a good night’s sleep, according to a newly released, landmark study from The Center for Health Design (CHD).

Evidence-Based Design Meets Evidence-Based Medicine: The Sound Sleep Study” is the first study to identify decibel (dB) levels at which 14 typical hospital sounds are too loud for undisturbed sleep. The study’s results and recommendations are expected to drive innovation in design, construction, materials, equipment and care protocols to improve acoustics in health care environments, positively impacting medical outcomes and increasing safety.

The sound-sleep study was conducted by two Harvard researchers in Massachusetts General Hospital’s sleep laboratory. While participants slept, researchers played recordings of 14 different noises typically heard in a medical-surgical unit. Arousal information confirmed that at levels commonly experienced by patients, the selected hospital sounds significantly disrupted sleep.

For example, at the lowest sound level tested, 40 dB, intravenous alarm and phone signals aroused 88 percent to 94 percent of subjects; human voices aroused 70 percent to 75 percent of subjects; and the sounds of an automatic towel dispenser, ice dispenser, door closing and toilet flushing aroused 35 percent to 73 percent of subjects.

Improving the Acoustic Environment
National surveys of hospital patients have shown that room noise levels received ratings that were worse than other quality of care indicators. Similarly, disrupted and/or limited sleep has been demonstrated to have adverse impacts on several important health measures and outcomes including blood pressure, weight gain, heart disease, pain, stress levels, and inflammation.

Getting a good night’s sleep contributes to higher patient satisfaction and aids in recovery, resulting in improved medical outcomes, shorter hospital stays and reduced costs.

The new sound-sleep study contributes to the growing effort of improving environments of care and related health outcomes. It contributes scientific evidence validating the provision of minimum acoustic standards recently established in the 2010 edition of the Guidelines for Design and Construction of Health Care Facilities.

Sponsored by CHD through its Research Coalition, the Facilities Guidelines Institute, and the Academy of Architecture for Health Foundation, the study's principal investigators included Jo Solet, Ph.D., Orfeu Buxton, Ph.D., and Jeffrey Ellenbogen, MD, all from the Harvard Medical School, Division of Sleep Medicine.

“The new sleep-sound study provides valuable knowledge to the growing field of evidence-based design,” says Debra Levin, president and chief executive officer, CHD. “The report is a valuable tool for designers who are working to improve the quality of health care environments. We look forward to seeing the findings of this study utilized in the field.”

“This is one the most exciting studies looking at the impact of hospital sounds on patient well-being,” adds Paul Barach, co-chair of CHD’s Research Coalition. “This is an important and new frontier that promises to enrich our understanding of how external factors, including the sounds and vibrations in health care facilities, can improve the quality of care that health care delivers.”

Evidence-Based Design Meets Evidence-Based Medicine: The Sound Sleep Study” is available by free download from CHD’s online store,, under White Papers & Reports.

The Guidelines for Design and Construction of Health Care Facilities is available from the Facility Guidelines Institute at

About The Center for Health Design
The Center for Health Design (CHD) formed in 1993, is a nonprofit research, education and advocacy organization of forward-thinking health care, elder care, design and construction professionals and product manufacturers who are leading the quest to improve the quality of health care facilities and create new environments for healthy aging. The CHD Research Coalition promotes the dissemination of research that contributes to therapeutic, safe, efficient and effective health care settings. The group also strives to support projects that fill critical gaps in the field of evidence-based design (EBD) while growing the network of researchers engaged in EBD by rewarding funds to select EBD research projects. For more information, visit