21. The computer-readable medium of claim 15 , further comprising:: updating or modifying the keyword detection based at least in part on words within the audio input; and updating the previously stored acoustic model based at least in part on the audio input.
15. A computer-readable medium having computer program logic recorded thereon, execution of which, by a computing device, causes the computing device to perform operations comprising: receiving an audio input from a device via a communication network, the audio input based at least in part on speech input, wherein the audio input is the result of preliminary signal processing comprising keyword detection by the device prior to receipt of the audio input; performing speech recognition on the received audio input based at least in part on a previously stored acoustic model in order to recognize a command; and transmitting data to the device, responsive to the command, via the communication network using communication channels comprising: a high bandwidth communication channel configured to transmit data supporting audio or video output at the device, and a low bandwidth communication channel configured to transmit data supporting control signals for operation of a primary functionality component of the device, wherein the data comprises audio data generated to be consistent with audio data generated by the device based on a type of the device.