Effects of pitch accent type on interpreting information status in synthetic speech

Unit selection synthesis has made it possible to produce speech with high quality. However, because it allows little control over intonation, it may produce speech with contextually inappropriate intonation. In the signalling of information status, intonation, in particular, choice of pitch accent, has been taken into account in a number of dialogue systems. Previous research shows that this can improve the perceived intonational appropriateness of synthetic speech. Using an eye-tracking paradigm, this study investigates how pitch accents H*L and L*H and deaccentuation affect the interpretation of information status in synthetic speech in English. It was found that H*L biases listeners’ interpretation to new information but L*H, like deaccentuation, biases listeners’ interpretation to given information. These results indicate that listeners can and do make use of intonational cues in the interpretation of information status in synthetic speech and lend strong support to the integration of intonational signalling of information status into unit selection synthesis.