Abstract:We investigate the effect of speaking rate and pauses on the perception of spoken Easy Japanese, which is Japanese language with mostly easy words to facilitate understanding by non-native speakers. In this research, we used synthetic speech with various speaking rates, pause positions, and pause lengths to investigate how they correlate with the perception of Easy Japanese for non-native speakers of Japanese. We found that speech rates of 320 and 360 morae per minute are perceived to be close to the ideal speaking rate. Inserting pauses in natural places for Japanese native speakers, based on the dependency relation rule of Japanese, makes sentences easier to listen to for non-native speakers as well, whereas inserting too many pauses makes the sentences hard to listen to.