Anker's Soundcore Liberty 4 earbuds can monitor your heart rate
Among them are the Liberty 4 earbuds, which can track your heart rate. The heart rate sensor is in the right earbud, so you'll need to wear that one to use the feature. When it's measuring your blood oxygen levels, the earbud will emit a red light. Soundcore hasn't disclosed the waterproof rating, which is odd given that heart-rate tracking functions are closely linked to workouts.
Soundcore says an algorithm can tune the spatial audio function depending on whether you're watching a movie or listening to music. The earbuds offer dynamic head tracking too. Soundcore is using a gyroscope to ensure sound always surrounds you. In addition, Liberty 4 offers adaptive noise canceling and personalized sound.claims, and 28 hours in total before you need to top up the charging case's battery.