Toward the realization of spontaneous speech recognition and summarization

Although high recognition accuracy can be obtained for speech in the form of reading a written text or similar by using state-of-the art speech recognition technology, the accuracy is quite poor for freely spoken spontaneous speech. From this perspective, a five-year national project for raising the technological level of speech recognition and understanding commenced in Japan in 1999. The project focuses on building a large-scale spontaneous speech corpus and acoustic and linguistic modeling for spontaneous speech recognition and summarization. This paper reports some results of preliminary experiments which have been conducted at Tokyo Institute of Technology. Experimental results show that acoustic and language modeling based on the actual spontaneous speech corpus is far more effective than modeling based on read speech. It was also shown that our proposed automatic speech summarization method could effectively extract relatively important information and remove redundant and irrelevant information.