Speech processing research in Japan started in the 1940s. While it has produced high quality results, many works were described only in Japanese and were not necessarily made available to the global community. In the 1990s, research on spoken language processing became so successful that it was extended to large vocabulary, continuous speech recognition, corpus-based speech synthesis, spoken dialogue systems, multi-modal interfaces and speech-to-speech translation systems, which are all covered by this book. It is believed that most of the basic ideas and technologies behind current spoken language systems were established by 2000. This book provides a compendium of the prominent studies on such prototypes of spoken language systems developed in Japan. This book is a comprehensive introduction to the major works conducted at Japanese research institutes that are developing spoken language systems.