Apple began discussing integrating health sensors into future sports-oriented headphones in a patent application that was published back in April 2009 and filed in 2008. Apple s engineers noted at the time that "The sensor can also be other than (or in addition to) an activity sensor, such as a psychological or biometric sensors which could measure temperature, heartbeat, etc. of a user of the monitoring system." After filing a series of patents in 2020-2021 on AirPods with health sensors, earlier this month Apple s Machine Learning (ML) Research team published a technical paper on using specialized health sensors into future AirPods