Google announced that they have acquired an Israel-based startup SlickLogin. The company, which debuted its product around half a year ago, specializes in a new hassle-free form of authentication based on audio signals alone. Sound-based passwords are the future, according to SlickLogin. Presumably, Google thinks so too, hence the acquisition.
So how does SlickLogin work? Well, it directs your PC to produce nearly inaudible sound from the speakers, which are picked up by your Smartphone. This in turn is picked up by the app, which sends the data over a secure network. Thus, SlickLogin can verify that the owner of the PC and the Smartphone, the same person, is trying to log into a service, effectively completing authentication with little to no input from the user's end.
Whether Google uses SlickLogin's product as a complete password system, or part of a two-step authentication, remains to be seen.