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.