1. A method comprising: receiving, at a network-based system configured to generate acoustic models and language models, inputs from a remote client via an application program interface, the inputs comprising: a feature stream of features extracted from speech processed by the remote client using a feature extraction algorithm which operates independent of the network-based system; and a transcription of the speech; generating an acoustic model according to an acoustic feature identified within the feature stream from the features extracted from the speech; generating a language model according to the transcription; and transmitting the acoustic model and the language model to the remote client.