1. A computer-implemented method comprising: receiving a request to update an existing speech recognition model for recognizing a particular term by a speech recognizer on a mobile device, wherein the request references a textual representation of the particular term and includes a recording of a user of the mobile device speaking the particular term or a set of features extracted from the recording, wherein the request specifies an updated speech recognition model type to be generated, and wherein the updated speech recognition type is a different speech recognition model type than the speech recognition model type of the existing speech recognition model; generating the updated speech recognition model for recognizing the particular term based on the request; and transmitting the updated speech recognition model for recognizing the particular term to the mobile device, as a replacement for the existing speech recognition model for recognizing the particular term.