Apparently, the same is for our ear canals too. And now, a researcher is attempting to use that to create a new kind of biometric device.
The human ear canal is designed so that it reflects sound waves back in on itself, allowing your auditory receptors to better pick up sound. Something scientists have realised about this is that each person's ear canal is a little different. The way sound is absorbed produces a unique signature that's based on the geometry of a person's ear canal.
Zhanpeng Jin, a computer scientist at the University at Buffalo, says he was inspired to use this for authentication because of how many students roam around campus with earphones in. "We have so many students walking around with speakers in their ears," he said in a statement. "It led me to wonder what else we could do with them."
So Jin developed EarEcho. It's a new biometric tool that uses off-the-shelf products, including a pair of in-ear buds and a tiny microphone. Jin and his team used them to build a device that plays a sound into a person's ear and records the unique signature it leaves through the canal. It then sends it to the phone the device is paired with over Bluetooth and has it analyse the signature for comparison. If it matches, the device then authenticates and unlocks the phone.
"It doesn't matter what the sound is, everyone's ears are different and we can show that in the audio recording," Jin says. "This uniqueness can lead to a new way of confirming the identity of the user, equivalent to fingerprinting."
Jin and his team tested the device with various audio samples, including speech and music. When playing the sound for just a second, it was 95 percent accurate, which improved to 97.5 percent during a three-second window.
"Think about that," Jin said. "Just by wearing the earphones, which many people already do, you wouldn't have to do anything to unlock your phone."
Jin's plan now is to have it eventually become the go-to authentication feature for crucial tasks like making mobile payments, bypassing the need for a password or PIN. And it'll be more secure than a fingerprint, because this sort of data is a lot harder to steal.
The university has currently filed for a provisional patent for the technology and is awaiting a response.