1. Apparatus for generating and testing speech models, said apparatus comprising: a data collection unit operable to collect and store utterance data indicative of the pronunciation of one or more words by one or more speakers; a speech model generation unit operable to generate speech models of words, utterances of which have been collected by said data collection unit; and a testing unit operable to test the accuracy of the matching of utterances collected by said data collection unit to speech models generated by said speech model generation unit and to generate a visual display of the results of said testing by said testing unit.