Researchers at Google have demonstrated how regular earbuds with Active Noise Cancellation (ANC) can transform into heart rate monitors without the need for additional hardware or sensors.
Google researchers showcased this technology at Mobicom 2023, held in Madrid from October 2-6, 2023. They also shared their research paper on the technology, titled “APG: Audioplethysmography for Cardiac Monitoring in Hearables.”
The study was conducted over eight months with 153 participants to test APG in various scenarios.
This technology employs a pulse-like signal to monitor heart rate. The headphones emit a sound into one’s ear and then listen for the echoes. When blood vessels change, they induce tiny variations in the ear, causing corresponding changes in the echoes, thus displaying the individual’s heartbeat.
Using the collected data, Google developed algorithms to interpret these echoes and devised a method to determine heart rate and its fluctuations through sound. This new approach can monitor heart rate using regular noise-canceling headphones, even while a person is in motion or listening to music. The researchers added that this technology can be integrated into existing earbuds through a simple software update.
Google’s study demonstrates that APG is effective in measuring heart rate (with a 3.21% margin of error) and tracking changes in the heartbeat (with a 2.70% margin of error) for most individuals. Furthermore, they claim that this technology surpasses existing light-based photoplethysmograph (PPG) and electrocardiogram (ECG) sensors, which typically add extra weight, cost, and drain the device’s battery life.