8. A method comprising: under control of one or more computing devices comprising one or more processors, accessing a voice activity decision corresponding to one or more frames of a media file, the voice activity decision being generated by a VAD module; after speech recognition of the one or more frames of the media file, receiving feedback associated with the voice activity decision that represents a relative accuracy of the voice activity decision, the media file being processed asynchronously such that each of the one or more frames is accessed prior to the generating the feedback, the feedback being generated by a speech recognizer; and enabling use of the feedback to guide voice activity detection (VAD) for one or more subsequent frames of the media file.
8. A method comprising: under control of one or more computing devices comprising one or more processors, accessing a voice activity decision corresponding to one or more frames of a media file, the voice activity decision being generated by a VAD module; after speech recognition of the one or more frames of the media file, receiving feedback associated with the voice activity decision that represents a relative accuracy of the voice activity decision, the media file being processed asynchronously such that each of the one or more frames is accessed prior to the generating the feedback, the feedback being generated by a speech recognizer; and enabling use of the feedback to guide voice activity detection (VAD) for one or more subsequent frames of the media file. 12. A method as recited in claim 8 , wherein the feedback is leveraged to update models associated with a VAD module that are used for VAD.