Researchers from the University at Buffalo in the US are devising a way for smartphone users to unlock their devices – using their ears.

Using earbuds could let users access their phones through a new gadget currently named EarEcho. This biometric tool uses modified wireless earbuds to authenticate smartphone users by analysing the unique geometry of their ear canal.

The inspiration for the device came after a professor at the university considered alternative uses for earbuds.

Speaking on the research, professor Zhenpeng Jin said: “We have so many students walking around with speakers in their ears. It led me to wonder what else we could do with them.”

Researchers developed the prototype device using off-the-shelf products, including a pair of in-ear earphones and a small microphone.

When a sound is played in a person’s ear, the sound reverberates through and is absorbed by the ear canal, researchers explained. This helps create a unique signature that can be recorded by the earbud microphone.

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

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20 test subjects listened to audio samples that included a range of speech, music and other audio content, with the team conducting research in different settings – such as on the street or in a shopping centre.

Tests conducted as part of the project proved to be roughly 95% effective when given one second to authenticate the subjects, Jin said. The effectiveness of the devices also increased to around 97% when it continued to monitor the subject in three-second windows.

While the EarEcho could offer smartphone users an alternative means of authentication and cut out the need for passwords or fingerprints, Jin suggested the “greatest potential” of the device could be its ability to continuously monitor users.

EarEcho works whenever a user is listening to their earbuds and is a passive system. This means that users could be able to authenticate wherever and whenever with ease.

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