10. 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: receiving, by a speech recognition model training system and from a client device, a request to generate a new speech recognition model for the client device, wherein the request includes: (i) one or more features extracted from speech data by a feature extractor on the client device, and (ii) metadata regarding the speech recognition model to be generated; generating, by the speech recognition model training system and using the one or more features extracted from speech data by the feature extractor on the client device, the new speech recognition model according to the metadata; and transmitting, by the speech recognition model training system and to the client device, at least a portion of the new speech recognition model.
10. 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: receiving, by a speech recognition model training system and from a client device, a request to generate a new speech recognition model for the client device, wherein the request includes: (i) one or more features extracted from speech data by a feature extractor on the client device, and (ii) metadata regarding the speech recognition model to be generated; generating, by the speech recognition model training system and using the one or more features extracted from speech data by the feature extractor on the client device, the new speech recognition model according to the metadata; and transmitting, by the speech recognition model training system and to the client device, at least a portion of the new speech recognition model. 14. The system of claim 10 , wherein the speech recognition model type information comprises data that specifies that the speech recognition to be generated is a word processing-type speech recognition model or a voice dialing-type speech recognition model.