21. The server apparatus of claim 17 , wherein the processor is further configured to: generate the speech model for each of the plurality of user spoken utterances; and measure a distance value between each of the generated speech models and every other generated speech model; wherein the user spoken utterance is selected based on the measured distance values between the speech model for the selected user spoken utterance and every other generated speech model.
22. The server apparatus of claim 21 , wherein the generated speech models are Hidden Markov Models.