Fast word-graph generation for spontaneous conversational speech translation

This paper introduces the latest advances in research at ATR on speech translation for spontaneous conversations, especially focusing on speech recognition efforts. For recognition, we employ a word search technique that generates moderate sized word graphs in real-time. To cope with a variety in length of utterances, e.g., word, phrase, sentence fragment, sentence, and concatenated sentences in spontaneous speech, we have adopted a two pass search strategy that uses variable-order word n-gram statistics in the first stage and task dependent language constraints in the second stage. This strategy is evaluated using the ATR Travel Arrangement corpus