13. A system comprising: one or more processors; memory communicatively coupled to the one or more processors for storing: a voice activity detection (VAD) module configured to: assign a probability to a first frame of a media file that represents a likelihood that the first frame includes speech; and update the probability of the first frame based at least in part on one or more frames within a frame window; assign a probability to a second frame within the frame window, the probability assigned to the second frame representing a likelihood that the second frame includes speech, the second frame being subsequent to the first frame; and update the probability of the first frame based at least in part on the probability of the second frame.
13. A system comprising: one or more processors; memory communicatively coupled to the one or more processors for storing: a voice activity detection (VAD) module configured to: assign a probability to a first frame of a media file that represents a likelihood that the first frame includes speech; and update the probability of the first frame based at least in part on one or more frames within a frame window; assign a probability to a second frame within the frame window, the probability assigned to the second frame representing a likelihood that the second frame includes speech, the second frame being subsequent to the first frame; and update the probability of the first frame based at least in part on the probability of the second frame. 15. A system as recited in claim 13 , wherein the VAD module is further configured to update the probability of the first frame prior to the first frame being processed by a speech recognizer.