The device would not replace a “code blue,” Dr. Ozcan said, but it could potentially reduce the number of beeps, as caregivers would be alerted that a patient was veering into a danger zone before an alarm is triggered.

The challenge, said Dr. Ozcan, is balancing the needs of patients and clinicians, who would have to learn and integrate new devices into their work flow.

Dr. Ozcan said she was hopeful that the research done at her lab could be applied in other settings, such as air traffic control rooms, or would be relevant for research on how sound influences health in general, especially in work environments.

“We owe it to the community and health care,” she said.

Yoko Sen has since recovered from her illness, but the bleating monitors are still “the soundtrack of my life,” she said.

Through her start-up Sen Sound based in Washington, she has collaborated with medical device engineers to create new tones for home heart monitors, and with interior designers to build a so-called tranquillity room, where clinicians can relax, making them less likely to slam doors or talk loudly.

During a person’s last moments, her eyes might be closed, his nose covered by a ventilator, her food ingested by tube. Unless someone is holding her hand, she might feel nothing.

“For patients who die in the I.C.U., that sound of the alarm might be last sound they hear,” she said.