New Tech Turns Headphones into Heart Monitors
The earphones that can listen to your heart.
At the Healthcare Device Exhibition in Japan, Kaiteki Institute Inc and Bifrostec have developed and demonstrated a new tech which will surely excite health nuts everywhere. Their demonstration showed that it was possible to use the slight changes in pair pressure in the ear canal to detect the wearer's heart rate.
It's pretty interesting stuff since many earphones are terrible at getting a perfect, air-tight seal, which is essential in being able to contain and detect the pressure wave so that it can be used effectively. That said, the team used headphones that cost about $8; they say that it doesn't require any special kind of headphones. If the device and software can be installed in a smartphone, for example, then it could handle all of the processing and then report the user's heart rate directly.
A Bifrostec representative said, "There are many people who listen to music while jogging… with the new technology, it becomes possible to measure their pulse waves without any special effort."
In addition to the earphone tech, the team showed off a ring prototype sensor that operated on the same basic principle, as well as software that checks autonomic nerves by using data from either sensor. The autonomic or visceral nervous system is largely responsible for all of the core functions of the human body including heart rate, digestion and perspiration. It operates below the level of consciousness and can provide substantive information on overall health.
As much as tech has revolutionized our lives already, with this we'll have one fewer excuse to stay healthy and fit.

I would not think so, since sound waves would interfere with the ones coming from the heartbeat. I would guess there is an app that pauses the music while getting the 'pulse'. At the same time, there are apps that measure heartbeat by using the LED and camera, so this would only be useful for those that lack either (hard to find such instances in current smartphones).
Since the point of the thing most likely is to provide effortless and non-intrusive measurements by reusing a transducer most people already wear anyway, cutting the sound and requiring user intervention would render this thing pointless - people will most likely far prefer uninterrupted music apart from possible rate monitoring warnings to tell you your heart rate either dropped below your workout's minimum level or exceeded the maximum.
With echo cancellation, it should be possible to detect the pulse even with music playing but that would require an ADC with high enough resolution to pick up the back-EMF from the headphones from under the sound signal.
Monitoring heartrate with a microphone attached to your body is nothing new so if they have to stop music to make measurements, that would make it pretty much un-news.
Assassin tool of the future!
Since the point of the thing most likely is to provide effortless and non-intrusive measurements by reusing a transducer most people already wear anyway, cutting the sound and requiring user intervention would render this thing pointless - people will most likely far prefer uninterrupted music apart from possible rate monitoring warnings to tell you your heart rate either dropped below your workout's minimum level or exceeded the maximum.
With echo cancellation, it should be possible to detect the pulse even with music playing but that would require an ADC with high enough resolution to pick up the back-EMF from the headphones from under the sound signal.
Monitoring heartrate with a microphone attached to your body is nothing new so if they have to stop music to make measurements, that would make it pretty much un-news.
What you said is mostly true but unfortunately, I think they haven't gotten clever enough to do this without cutting the sound. That doesn't mean it's "un-news". The point is to make detecting heart rate more convenient but I think the research is still far away from being completely invisible and in the background.
If they have to cut sound to make measurements then there is nothing really new about it: the fact that speakers can be used as microphones has been known for nearly 100 years. The only thing you need to turn any odd pair of microphones into an HRM is an amplifier with low enough noise, a low-pass filter and some form of counter circuitry. Relatively trivial.
Heck, even doing that with music playing shouldn't be too hard if you can pass the audio through a 20-20kHz filter for audio on the output path and a 0-10Hz LPF for the HRM, which eliminates the need for echo cancellation and high precision ADC.