Prosodic cues for rated politeness in Japanese speech

Abstract

In order to examine potential acoustic cues for politeness in Japanese speech, F0 and temporal aspects of polite and casual utterances of two question sentences spoken by 6 male native speakers were acoustically analysed. The analysis showed that F0 movement of the final part of utterances and speech rate of utterance were consistently differently used in these different speaking styles across all the speakers. Perceptual experiments with listeners confirmed that these acoustic variables, which were manipulated using digital resynthesis, had an impact on politeness perception. It was shown that how the final intonation of a sentence is spoken had a great impact on politeness judgements. In some cases the duration and F0 characteristics of the final vowel did change the overall impression of the utterance's politeness. An experiment which used speech rate variations of a polite utterance showed the important role of this variable in perceived politeness. Politeness ratings showed an inverted U-shape as a function of speech rate, but differed according to particular speakers. The speech rate of listeners was found to affect their utterance rate preference; listeners preferred rates close to their own. These findings suggest that listener characteristics should be considered important in politeness speech research.