Heart Rate Can Be Measured With ANC Earbuds With Google Update

A group of researchers from the US internet company Google has managed to find a seemingly simple way to enable all headphones with active noise cancellation to detect the heart rate of their wearers via a software update

Any ANC earbuds can be modified using software

In theory, in-ear headphones that are factory-installed with a function to actively suppress ambient noise can apparently also be used to monitor the user’s heart rate. According to a research paper by some Google researchers, this is made possible by the built-in microphones and some software tricks.

The Google team calls its approach audio plethysmography (APG) for heart rate monitoring in hearables, according to 9to5Google. In this type of APG, the speakers in the headphones emit a very low-frequency sound signal and the echoes of these sounds are picked up by the microphones in the headphones that are actually used for noise cancellation.

Using a special mathematical model, the ultrasound echoes are then converted into heart rate values. The system takes advantage of the fact that the volume of the human ear canal changes with the deformation of the veins in the ear caused by the blood flow, which also changes the ultrasound echoes. Based on these differences, the heart rate can be determined and monitored permanently.

According to Google’s research team, their approach also works when the headphones are being used to play audio or the user is engaged in sporting activities such as jogging. The skin color, poor fit, or the size of the ear canal do not play any role, it goes on to say. The impact on the battery life of the headphones should be minimal, even with continuous heart rate monitoring.

According to Google, it even conducted an eight-month study with over 150 participants to prove that the new APG system works under a wide range of conditions. The accuracy was reportedly very high, and even fluctuating heart rates could be reliably determined.

The researchers now want to test the reliability under difficult conditions, for example in more demanding sports. It was not known whether and when the technology could be integrated into finished Google products.