Biometrics, Essays, Hearing Healthcare

Bringing Biometric Sensors to our Ears


Valencell + Sonion

News broke last week that Sonion, a leading components manufacturer for ear-worn devices, had led a $10.5 million Series E round of investment into Valencell, a pioneer in the biometric sensor manufacturing industry. In exchange for its investment into Valencell, Sonion now has exclusivity on Valencell’s bio-sensor technology for the ear-level space. Sonion plans to integrate these biometric sensors into the component packages that they’re developing for hearing aid and hearable manufacturers. This new strategic partnership will help Valencell grow its footprint by leveraging Sonion’s distribution network of ear-worn devices, and ultimately expose more end-users to Valencell’s biometric sensor technology.

The March toward the Ear

The type of sensor that Valencell develops is referred to as an optical PPG (photoplethsymography) sensor. It can record measurements such as your heart rate using a light to illuminate the skin and measure changes in light absorption. It detects the volume of blood and the pressure of the pulse based on the light absorption, allowing for an accurate heart rate measurement. If you’ve used an Apple Watch and have used the Heart Rate app, you’ll notice that a green light on the underside of the Watch lights up. That’s a PPG sensor.

Image result for apple watch ppg sensor
Image from Cult of the Mac

There are a number of reasons that companies like Valencell are so keen on embedding these type of sensors in our ears. Valencell president, Dr. Steven LeBouef, made the case why the ear is the most practical spot on the body to record biometric data:

  1. Due to its unique physiology, the ear is one of the most accurate spots on the body to measure physiological information,
  2. One can measure more biometrics at the ear than any other single location on the body,
  3. Environmental sensors at the ear (exposed to the environment at all times) can assess what airborne vapors and particles one is breathing and expiring, and
  4. People already wear earbuds, headphones, hearing aids, etc. routinely throughout their lives, making compliance quite high.

So in essence, the ear is the most precise, most robust, and most exposed area on the body for recording this information, all while serving as a location where we have already become accustomed to wearing technology. So, this is a no-brainer, right? Why aren’t our ear-worn devices already using these sensors ?

The Challenges of Really Small Devices

As I wrote about in my last post around the innovation happening in our hearables and hearing aids, it can be rather daunting to try and cram all this technology into really small devices that fit in our ears. Battery life is always a challenge because with small devices, there’s only so much power that can go around. Valencell has been able to lower the power consumption of its sensors by a multitude of 25X over the past 5 years, but will still need to find ways to drop that even lower in order for these sensors not to be viewed as major battery drains. Price is another obstacle, as these sensors currently add too much of an incremental manufacturing cost not feasible for the lower-cost end of the market.

That’s why this partnership is so exciting to me. What Sonion really brings to the table here is an expertise in reduction. Reduction in size, price and power consumption, which have been three of the biggest obstacles in making the embedding of these sensors feasible into ear-worn devices.

The Benefits of Putting Biometric Sensors in our Ears

There are two sets of use cases that are currently clear to me around biometric data. The first would be fitness applications. Just think of your hearing aid or earbuds capturing the same fitness data that an Apple Watch or Fitbit records. I think this set of applications gets really interesting when you layer in smart assistants, which can be used to guide or coach the user, but that’s another post for another day. For now, let me just point out that whatever you can do with your wrist-worn wearable today from a data collection standpoint, would seemingly be feasible with our ear-worn wearables that are around the corner.

The next, and much more exciting use case, is around preventative health. If you just search, “Apple Watch saves life,” you’d be amazed at all the people out there who were alerted by their Apple Watch that there was something funky going on with the data that was being logged. Here are a few examples:

  • Teen’s Life Saved by Apple Watch that Alerted her of Heart Condition
    • 18 year old girl is sitting in church when her Apple Watch told her to seek medical attention due to her sitting heart rate spiking to 120-130 beats per minute. The doctors found out she was experiencing kidney failure.
  • Apple Watch Credited with Saving a Man’s Life
    • 32 year old man begins bleeding out of the blue, is prompted by his Apple Watch to seek immediate medical attention, he then calls 911 and by the time the ambulance arrives he has lost 80% of the blood. An ulcer had unknowingly burst in his body and doctors were cited as saying that the Watch notification gave him just enough time to call for help.
  • 76 year old man says Apple Watch Saved his Life
    • “After an electrocardiograph machine indicated something was wrong, doctors conducted tests and discovered that two out of his three main coronary arteries were completely blocked, with the third 90 percent blocked.”
  • And of course, who can forget this guy:Pulmonary embolism tweet.JPG

This is a big part of why I am so bullish on the future of ear-worn devices. I imagine that we’ll see tons of stories like these emerge when these same type of sensors that are currently in the Apple Watch start making their way into our ear-worn devices. We know that the ear is a perfect place to record this type of data, and there’s no new adoption curve for these devices – we’re already wearing tons of things in our ears!

Hearing aids in particular, with their form factors that are conducive to all day usage, really strike me as the perfect preventative health device. The largest demographic of hearing aid wearers (75+ years old), is probably in need of a health monitoring tool like this the most too. As these sensors mature and become more capable at detecting a wider variety of risks, so too will the value proposition of these devices grow.

I don’t think it’s too far-fetched to think that in the not-too-distant future, one’s physician might actually even “prescribe” a preventative health device to monitor a pre-existing condition or some type of medical risk. I can picture them showing a list of body-worn, certified, “preventative health,” devices, and in that list would contain a range of options from the Apple Watch, to sensor equipped hearing aids, to cutting edge hearables. Look no further than the software development kits that Apple has been rolling out over the past few years, and you’ll see that biometric data logging and sharing is very much on the horizon. Exciting times indeed!

-Thanks for Reading-



2 thoughts on “Bringing Biometric Sensors to our Ears”

  1. That was a good one! 👍 interesting alternative route to Oura Ring or Whoop, I’m guess in the ear you can measure heart rate variability pretty easy (why Oura ring is a ring, easier to do HRV from the finger).

    Biomedical hearing devices could also have an interesting use case for sleep tracking (i.e. people want it to be quiet when they sleep, noises wake people up, etc.) There are a few sleep tracking apps (Sleep Cycle, Pillow) that record sounds during sleep, compare with NREM/REM sleep, and allow you to play back disruptive sounds in the morning. I wonder if it’s easier to track sleep brainwave activity from the ear??

    –Ben Standefer

    Sent via Superhuman iOS ( )

    1. Hi Ben,

      Thanks a lot for reading and commenting! Here’s why Valencell argues that the ear is the prime spot on the body for this type of data logging: “The ear is stable, with very limited movement even when the body is in motion. Also, because it is mainly cartilage and arterioles, there are fewer disturbance factors. The ear boasts an ideal arteriole bank between the anti-tragus and concha of the ear; since this arteriole bank is directly connected to the carotid artery system, blood flow characteristics measured at this location can provide a true picture of what’s going on in the heart. Moreover, this region of the ear does not interfere with the ear canal or audio electronics, and it is more uniform across a larger population than other ear locations, making earbud design more flexible. Add to that the comfort level consumers already have with earbuds, and this location ranks highly.”

      It’s also interesting that you mention sleep, as Bose just released a product called Sleep Buds. Currently, it’s more of a noise cancellation device, but the fact that people are sleeping with said device, makes me think that if this type of device was to have embedded sensors of some type, that there would be a lot of interesting use cases that emerge from that type of data collection. It’s going to get really interesting, pretty quickly as these devices start getting outfitted with sophisticated sensors.


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