A Free Online Accent and Intonation Dictionary for Teachers and Learners of Japanese.

We have developed the very first free online and free framework for teaching and learning Japanese prosody with features for word accent and phrase intonation. This framework is called OJAD (Online Japanese Accent Dictionary) [1], which provides three functions. 1) Visual, auditory, systematic, and comprehensive illustration of patterns of accent change (accent sandhi) of verbs and adjectives. Here only the changes resulting from twelve kinds of fundamental conjugation are focused upon. 2) Visual illustration of the accent pattern of a given verbal expression, which is a combination of a verb and its postpositional auxiliary words. 3) Visual illustration of the pitch pattern of an any given sentence and the expected positions of accent nuclei in the sentence. The third function is implemented by using an accent change prediction module that we developed for Japanese text-to-speech (TTS) synthesizers [2]. Subjective assessment by teachers shows very high pedagogical effectiveness of the framework. Index Terms: language education, Japanese prosody, accent sandhi, OJAD, TTS synthesizer, assessment experiment