Our ears may have built-in passwords

You are the victim of identity theft and the fraudster calls your bank to transfer money into their own account. But instead of asking them for your personal details, the bank assistant simply presses a button that causes the phone to produce a brief series of clicks in the fraudster's ear. A message immediately alerts the bank that the person is not who they are claiming to be, and the call is ended.
Our ears may have built-in passwords