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A new Canadian-led study into the effectiveness of medical alarms has revealed musical notes are “less bothersome” than industry-standard flat tones, which researchers believe could better alert health-care workers without compromising patient safety.

Researchers changed the sounds in medical devices to see if they were more effective in alerting users. Then, in a separate experiment, respondents rated how annoying they found each of the tones that were tested, preferring percussive tones to flat tones.

Findings of the study, conducted in Hamilton, Ont., and published in the British Journal of Anesthesia, offer a glimmer of hope for some health-care workers, who told CTVNews.ca of the fatigue alarm they experience.

“They drive me nuts,” says Heather McKenzie, a registered practical nurse, who says she hears them all day working in a busy kidney dialysis unit in Welland, Ont. “I know I have to respond but if I am in the middle of something important, it has to wait, causing a feeling of pressure, like a knot in my stomach or even nausea.”

Joseph Schlesinger, co-author of the study and an anesthesiologist and critical care physician at Vanderbilt University Medical Center in Nashville, told CTVNews.ca that he was exposed to these alarms on a daily basis and began hearing the alarm tones when he was trying to sleep at night.

The auditory alarms are built into IV units, heart monitors, and other drug pumps to alert staff to changes in a patient’s status and to make adjustments to medications and other therapies.

However, the alarms are more than an annoyance, though. In the US, according to FDA data, issues with hospital alarms contributed to 566 patient deaths between January 2005 and June 2010.

Michael Schutz, professor of music cognition at McMaster University, and lead author of the study, said in a press release issued by the university that efforts to cut down on noise pollution in hospitals have centered around reducing alarms rather than changing the sounds.

“It has been operating this philosophy of… the more annoying, the better,” Schutz told CTVNews.ca.

Schutz and Schlesinger used tones that are designed like musical notes which they describe as two wine glasses clinking together, with the sound then decaying with time.

The results show the experimental sounds are equally informative but far less grating. Researchers supplied CTVNews.ca with two examples of the alarms, which you can listen to below. One is the industry-standard flat alarm like those found on most medical devices, the other is an experimental percussive tone preferred by respondents.


After hearing both alarms, McKenzie was quick to choose her choice. “I like the musical sounding beeps better,” she told CTVNews.ca, adding that nicer alarms would mean “less-stress” at work.

“These new sounds are actually more alerting, they grab your attention better,” Schutz added. “But they don’t distract from your ability to understand speech. We want doctors and nurses to be able to communicate.”

The study’s findings show “the alarm can be softer than what we have now, and it doesn’t harm the perception of the alarm itself” added Schlesinger.

UK scientist Judy Reed Edworthy told CTVNews.ca the research offers more evidence that it’s time for device makers and regulators to take note.

“The work in this paper can help medical device companies to improve their alarms and improve patient safety as well as clinician fatigue,” said Reed, who is a professor of applied psychology (emerita) at the University of Plymouth. She has also worked with the International Commission on the Biological Effects of Noise.

It requires a shift in thinking, say the scientists, from treating all alarms as “emergencies” to being able to distinguish urgency from basic patient information.

“I think if we just called them auditory alerts, the whole challenge would become a lot clearer,” says Schutz. “If you have an alert on your phone… that conveys information without pulling you out of whatever else it is that you’re doing,” he said.

Dr. Schlesinger added that at least one medical device maker is bringing in sound research expertise to advise the company, a signal that the industry may be listening to the emerging data.