1. A method of automatically identifying a speaker; the method including: identifying a speaker by: receiving a test utterance from the speaker; determining a most likely one of a plurality of speaker models for the test utterance; and identifying the speaker associated with the most likely speaker model as the speaker of the test utterance; wherein the method includes generating the plurality of speaker models in the background by: receiving training utterances from the plurality of speakers in the background, without prior knowledge of the speakers who spoke the respective training utterances; blind clustering of the training utterances based on a predetermined criterion; and training for each of the clusters a corresponding speaker model; each of the models representing a speaker.