Newer apps do away with manual input and instead use a TV's audio to identify shows. Similar to music-identifying apps such as Shazam, the services sample audio from the TV about every 50 milliseconds and cross-reference that sound with an existing audio library. The apps can recognize what a person is watching in four seconds and then aggregate related content, including Twitter feeds, news stories, screenshots, clips and soundtracks. IntoNow, a start-up that Yahoo! purchased last spring, and California-based ConnecTV have had the most success. IntoNow is so accurate, in fact, that it can tell a baseball game at Yankee Stadium from one across town at Citi Field. But audio syncing is only a stopgap; even the most precise tablet algorithm is no match for a noisy room.