The shape of your ear could soon unlock your smartphone

19 Sep 2019

Image: © opolja/

Researchers have found a way to unlock a smartphone using earbuds designed to detect the unique shape of your ear canal.

A University of Buffalo team has developed a technology that could allow for earphone manufacturers to build biometric technology into them for unlocking a smartphone. Dubbed EarEcho, the work led by computer scientist Zhanpeng Jin uses modified wireless earbuds to authenticate smartphone users via the unique geometry of the user’s ear canal.

With its findings published to Interactive, Mobile, Wearable and Ubiquitous Technologies, Jin’s team said testing so far has shown it to be 95pc effective and he has filed a patent on the technology.

The prototype was built with off-the-shelf components, including a pair of in-ear earphones and a tiny microphone. Then, acoustic signal processing techniques to limit noise interference were developed along with a way to share information between EarEcho’s various parts.

When a sound is played in someone’s ear, it propagates through and is reflected and absorbed by the ear canal, all of which produces a unique signature identifiable by the microphone.

Infographic of an ear canal and EarEcho working.

Cross-section of the EarEcho. Image: University of Buffalo

Continual monitoring

“It doesn’t matter what the sound is, everyone’s ears are different and we can show that in the audio recording,” said Jin. “This uniqueness can lead to a new way of confirming the identity of the user, equivalent to fingerprinting.”

The recording is then sent by the earbuds’ Bluetooth connection to the phone for analysis. During testing, 20 subjects listened to audio samples that included a variety of speech, music and other content. These were all tested in different environmental settings – such as on a busy street – and with the subjects in different positions such as sitting and standing.

To achieve 95pc accuracy, it took one second to authenticate, and when expanded to three seconds authentication increased to 97.5pc.

While the technology is currently focused on being able to unlock a phone, Jin said that the eventual aim of EarEcho is for continual monitoring of the user. Arguing for this use, Jin said it would mean that because it is passive monitoring by its nature, it could eliminate the need for passcodes or fingerprints when making mobile payments.

“Think about that,” said Jin. “Just by wearing the earphones, which many people already do, you wouldn’t have to do anything to unlock your phone.”

Colm Gorey was a senior journalist with Silicon Republic