Google Audio Indexing is a Google Labs pilot project that uses its own speech recognition system, called GAudi, to find spoken words inside videos, and lets the user jump to the right portion of the video where these words are spoken.
Google Audio Indexing for the US Elections is a showcase for speech technology. You can use speech technology to find videos and to search for spoken content inside a video. You can also restrict your search to the content of a given video. The returned videos are ranked based on parameters like the spoken content, the metadata, the freshness.
Google Audio Indexing currently searches only those videos uploaded on the YouTube political channels. It enhances the YouTube player to display mentions of the query terms as yellow markers on the player timeline.