Google Audio Indexing (gaudi) uses speech technology to transform spoken words into text and leverages the Google indexing technology to return the best results to the user.
The returned videos are ranked based -- among other things -- on the spoken content, the metadata, the freshness.
Google periodically crawl the YouTube political channels for new content. As soon as a new video is uploaded to YouTube, it is processed by our system and made available in our index for people to search.
Google uses his own speech recognition system (called GAudi, for Google Audio Indexing), which powers both Google Audio Indexing and the Google Elections Video Search gadget.