7. The method of claim 1 , wherein updating the adaptive speech recognition model comprises: comparing the call audio signal with the adaptive speech recognition model; generating a confidence score based on the comparison; in accordance with a determination that the confidence score is at or above a predetermined threshold, updating the adaptive speech recognition model with the training data derived from the call audio signal; and in accordance with a determination that the confidence score is below the predetermined threshold, forgoing to update the adaptive speech recognition model.
1. A machine-implemented method, comprising: determining that a first user of a first mobile communication device is engaged in a call over a communications network; providing an adaptive speech recognition model comprising a speaker-dependent speech recognition model; after providing the adaptive speech recognition model, analyzing 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 updating the adaptive speech recognition model with training data derived from the call audio signal.