Media reports have revealed how AirPods have learned to recognize over 50 exercise modes. According to CNMO, Apple has simultaneously introduced tracking capabilities for over 50 types of exercise on AirPods, whereas achieving comparable levels of activity tracking in the Apple Watch era took years.
According to foreign media reports, ear canal PPG (photoplethysmography) signals demonstrate significant advantages in activity monitoring. Compared to wrist and fingertips, the ear canal offers superior vascularity, immunity to motion interference, and ambient light rejection. Apple's Director of Health Perception verified this through experiments: in exercises requiring a firm grip, such as strength training and rowing, wrist devices often struggle to stably measure heart rate, while earphones provide more consistent and stable blood flow signals.
Take the AirPods Pro 3 as an example. They utilize an innovative infrared PPG solution, which offers lower energy consumption, a deeper wavelength, and enhanced penetration. This allows them to penetrate deep into the densely vascularized ear canal tissue, capturing cleaner and more stable pulse signals, laying a solid foundation for accurate activity monitoring.
Furthermore, the AirPods Pro 3's sensor pulses infrared light approximately 250 to 256 times per second, cleverly combining data from the IMU (accelerometer and gyroscope) to effectively eliminate motion artifacts. Apple's Vice President of Perception and Connectivity explained that the Apple Watch already has extensive experience in accumulating motion signals, but migrating this capability to AirPods requires "translating" wrist motion observations into head motion observations.
To this end, Apple drew on the training principles of the Large Language Model (LLM) and meticulously trained a new Motion Foundation Model based on approximately 50 million hours of real-world motion data from the Apple Heart and Movement Study. This provides powerful technical support for AirPods Pro 3's tracking of over 50 sports.
