13. The system of claim 9 , wherein the operations comprise streaming the environmental audio.
9. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: generating, by a mobile device, an audio recording of (i) a question about an unidentified item of media content that a different device is playing in a vicinity of the mobile device, and (ii) environmental audio; in response to forwarding the audio recording to a front end server of a natural language processing system, receiving an answer to the question that is based on processing different portions of the audio recording by a speech recognition engine server associated with the natural language processing system and a content identification engine server associated with the natural language processing system; and in response to the question, providing, by the mobile device, the answer to the question about the unidentified item of media content.