New Technology Turns Earbuds into Sensors for Cardiac Function Tracking

Missed early changes in valve timing or rhythm can delay diagnosis and escalation of care. A research team at Carnegie Mellon University (Pittsburgh, PA, USA) has now created a way to extend long-term observation by turning everyday earbuds into sensors for micro-cardiac activity. The approach aims to make at-home monitoring more accessible for patients at risk of structural heart disease and arrhythmias.

The technology repurposes widely available earbuds as heart-vibration sensors that capture valve activity with near-clinical accuracy. By reversing the function of the built-in speaker, the system treats the speaker as a sensor that responds to tiny vibrations transmitted through the body from the beating heart. The resulting ear‑canal recordings target mechanical information that conventional consumer wearables do not provide.

The research team developed a machine learning pipeline that reconstructs detailed cardiac motion signals from the earbud recordings. The reconstructed waveforms closely match signals from medical‑grade, chest-mounted accelerometers and gyroscopes. In a feasibility study of 18 users, signals measured in the ear tracked the predictable propagation of heart vibrations through the body and aligned with chest measurements, yielding correlations between 0.88 and 0.95. These findings indicate the ear can serve as a stable vantage point for monitoring valve mechanics.

The researchers note that most existing consumer devices estimate heart rate, whereas this method listens to how the heart beats. They report potential applications in passive, at‑home monitoring of heart conditions, including atrial fibrillation, and in detecting valve disorders. The work will be presented at the 2026 Association of Computing Machinery Conference on Human Factors in Computing Systems, and is available as an arXiv preprint titled “LubDubDecoder: Bringing Micro‑Mechanical Cardiac Monitoring to Hearables”.

"Collecting these signals typically requires a clinical setting in which the patient lies down, removes their shirt, and is instrumented with accelerometers and gyroscopes," said Justin Chan, assistant professor of electrical and computer engineering and computer science, who advised the project. "Recordings are typically limited to a few minutes due to time constraints in busy clinics and patient discomfort during prolonged sessions. Our technology removes all of those obstacles and enables micro-cardiac monitoring at home. The secret sauce in our work is measuring the micro-cardiac rhythms with the built-in speaker."

"We discovered this works across different people and across different earbud types," said Siqi Zhang, an electrical and computer engineering Ph.D. student and lead author on the paper. "Instead of just measuring how fast your heart beats, it listens to how it beats. And that distinction matters. Mechanical timing abnormalities can precede more obvious symptoms. Subtle shifts in valve dynamics could signal disease progression long before a person feels shortness of breath."

"Most people already own earphones and listen to music. Now we can also monitor heart health at the same time," added Zhang.

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