Speaker's intentions conveyed to listeners by sentence-final particles and their intonations in Japanese conversational speech

We investigated listeners' perception of speaker's intention depending on sentence-final particles and their intonations in Japanese conversational speech in order to build a speech synthesis system that can express different intentions and subtle nuances. First, we clustered F0 contours derived from approximately 2000 sentence-final syllables and found the sentence-final F0 contours varied a great deal. Next, we selected six distinctive F0 contours that gave perceptually different intonations from among the cluster centroids, and subjectively evaluated synthesized sentence utterances that had various sentence-final particles and their intonations. Results showed that suitable combinations of a sentence-final particle and its intonation should be used to precisely convey the intention to the listeners, and whether the sentence was positive or negative also affected the listeners' perception of the intention.