Smartphone sensors that can recognize your fingerprint and your face are already becoming commonplace, but Amazon could have an entirely fresh take on the biometrics trend.

A recent patent from the e-commerce giant suggests the company is considering an ear-scanning security feature for future devices.

The concept was submitted way back in 2011, but only approved last week by the U.S. patent office. It describes a system in which a front-facing camera could use photo or video to analyze your ear and unlock a device automatically.

This could be particularly handy if you get a call or any other situation where you need to quickly lift your phoneup to your ear. Most of the time, however, this gimmick might not actually be very useful.

If Amazon does plan to put its idea into action, the Fire Phone seems like the clear place to start. The company already confirmed plans for a second-generation of the flagship phone, despite the current model’s failure to take off.

Considering the original device’s focus on unique and somewhat gimmicky features an ear-scanning camera could be an obvious addition, though that doesn’t mean it will help sell more smartphones.