18. The non-transitory computer readable storage medium of claim 17 , wherein the method is performed by said first mobile communication device having said one or more microphones.
17. A non-transitory computer readable storage medium storing one or more programs configured for execution by a device, 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.