Google wants to protect your password with sound.

Google has purchased Slicklogin ,  a three-person startup out of Tel Aviv, to help bolster the search giant's two-step authentication efforts.

 Today, if you are looking to fortify your Google account beyond a single password, the two-step authentication process consists of you first logging in with your password, and then entering a second verification code that’s sent to your
 phone by way of a text message, a phone call or by using Google’s Authenticator app.

SlickLogin would ostensibly automate second stage of this verification. Instead of having to wait for a call or a text
message or having to fumble around with the Authenticator app, you’d apparently just place your phone next to your computer.
Sound-based login startup joins Google tech chorus [AFP]

According to the AFP:

The technology involves sending barely audible sounds through computer speakers and then having the users’smartphones recognize the unique tones and respond in kind. It also reportedly factors in the location of smartphones.