13. A computing device comprising: one or more computer processors; one or more computer-readable media having instructions stored thereon that, responsive to execution by the one or more computer processors, perform operations comprising: receiving, via a network interface of the computing device, a wideband speech feature from a remote entity; determining an estimate of a narrowband speech feature based on the wideband speech feature; providing the estimate of the narrowband speech feature to a speech recognizer trained on the narrowband speech features; receiving, from the speech recognizer, speech-recognition results based on the estimate of the narrowband speech feature; assembling the speech recognition results received from the speech recognizer; and transmitting, via the network interface to the remote entity and for output or display by the remote entity, the assembled speech-recognition results based on the estimate of the narrowband speech feature.
13. A computing device comprising: one or more computer processors; one or more computer-readable media having instructions stored thereon that, responsive to execution by the one or more computer processors, perform operations comprising: receiving, via a network interface of the computing device, a wideband speech feature from a remote entity; determining an estimate of a narrowband speech feature based on the wideband speech feature; providing the estimate of the narrowband speech feature to a speech recognizer trained on the narrowband speech features; receiving, from the speech recognizer, speech-recognition results based on the estimate of the narrowband speech feature; assembling the speech recognition results received from the speech recognizer; and transmitting, via the network interface to the remote entity and for output or display by the remote entity, the assembled speech-recognition results based on the estimate of the narrowband speech feature. 15. A computing device as described in claim 13 , wherein the operations further comprise storing the wideband speech feature for training a second speech recognizer based on wideband speech features.