9. A system, comprising: one or more processors; memory; and one or more programs stored in the memory, the one or more programs comprising instructions to: determine that a first user of a first mobile communication device is engaged in a call over a communications network; provide an adaptive speech recognition model comprising a speaker-dependent speech recognition model; after providing the adaptive speech recognition model, analyze an outbound audio channel of a baseband unit of the first mobile communication device to obtain a call audio signal corresponding to audio input from one or more microphones of the first mobile communication device; and update the adaptive speech recognition model with training data derived from the call audio signal.
16. The system of claim 9 , wherein the training data derived from the call audio signal includes one or more speaker-dependent sound units; and updating the adaptive speech recognition model comprises: comparing at least a subset of the one or more speaker-dependent sound units to the adaptive speech recognition model; generating one or more adaptive speech vectors based on the comparison; and modifying the adaptive speech recognition model based on at least a subset of the one or more adaptive speech vectors.