Google can turn ANC earbuds into a heart rate monitor with no extra hardware – with interesting upsides

Google performed two sets of studies with 153 people that found APG “achieves consistently accurate heart rate (3.21% median error across participants in all activity scenarios) and heart rate variability (2.70% median error in inter-beat interval) measurements.”

Compared to existing HR sensors, it’s not impacted by skin tones. Ear canal size and “sub-optimal seal conditions” also do not impact accuracy.

So apart from the skin pigmentation advantage, there is also no extra device or hardware required, and wearing ear buds during exercise is a pretty common behaviour. The downside is that no-one really wears earbuds 24/7.

See https://9to5google.com/2023/10/27/google-anc-earbuds-heart-rate/