Finite-state speech-to-speech translation

A fully integrated approach to speech input language translation in limited domain applications is presented. The mapping from the input to the output language is modeled in terms of a finite state translation model which is learned from examples of input output sentences of the task considered. This model is tightly integrated with standard acoustic phonetic models of the input language and the resulting global model directly supplies, through Viterbi search, an optimal output language sentence for each input language utterance. Several extensions to this framework, recently developed to cope with the increasing difficulty of translation tasks, are reviewed. Finally, results for a task in the framework of hotel front desk communication, with a vocabulary of about 700 words, are reported.