Google recently acquired an Israel based startup called 'SlickLogin', which indicates that the company is making plans to replace passwords and even two-factor authentication methods with an inaudible sound unique to your phone and Google login.
SlickLogin has a patented technology where your passwords and two-factor authentication setups can be replaced with a unique and inaudible sound. Once enabled, the website's login page would typically listen to this inaudible sound via your phone and then granting access to your account. This could solve a lot of problems and overcome the possibility of your email account being hacked by someone. All you have to do is hold your smartphone near your PC with the website's login page, and the access will be granted.