A Study on Speech Rate Control of Common Japanese Utterances Based on an Objective and Quantitative Method

该项目的目的是研究由于各种因素导致的局部语音速率的变化，并为高质量的语音合成推导出语音速率控制规则。在两年期间(1997和1998)获得的主要结果如下：(1)开发了软件工具，用于有效地分析大量语音数据，并用于根据给定的本地语音速率分布来改变话语的局部语音速率。(2)话语大小对局部语音速率的影响孤立地和句子上下文中的‘bunsetsu’短语的局部语音速率的比较表明，接近句尾的差异更大，(3)全局语音速率对局部语音速率的影响对全局语音速率变化对局部语音速率的影响的分析表明，全局语音速率的增加往往导致音节较早部分的局部语音速率的增加，而整体语速的下降往往会导致音节后半部分的局部语速下降。(4)词语重音类型对局部语速的影响分析具有几乎相同的分段结构但不同的词语重音类型的词语的局部语速分析表明，重音类型对局部语速的时间模式有显著的影响。(5)强调对局部语速的影响对局部语速的影响对具有不同重音位置的同一句子的局部语速的分析表明，强调往往会导致发音的重音部分的局部语速下降，局部降低伴随着基频轮廓中重音分量的变化。

The aim of the project is to investigate the changes of the local speech rate due to various factors and to derive rules for speech rate control for high-quality speech synthesis. The main results obtained for the two-year period (1997 and 1998) are as follows.(1) Development of software tools for efficient analysis of a large amount of speech data, and for changing the local speech rate of an utterance according to a given local speech rate profile.(2) Effect of utterance size on the local speech rateComparison of local speech rates of utterances of a 'bunsetsu' phrase both in isolation and in sentence context revealed that the differences are greater toward the end of the sentence, and the pattern of change is affected by the syntactic role of the bunsetsu in question.(3) Effect of global speech rate on the local speech rateAnalysis of the effect of changes in the global speech rate upon the local speech rate revealed that an increase in global speech rate tends to cause an increase in the local speech rate at the earlier portion of a syllable, while a decrease in global speech rate tends to cause a decrease in the local speech rate at the latter portion of a syllable.(4) Effect of the word accent type on the local speech rateAnalysis of the local speech rate of words with almost identical segmental structures but different word accent types revealed that the accent type has a significant influence on the time pattern of the local speech rate.(5) Effects of emphasis on the local speech rateAnalysis of the local speech rate of utterances of the same sentence with different stress positions revealed that the emphasis tends to cause a decrease in the local speech rate at the stressed part of the utterance, and the local decrease is accompanied by a change in the accent component in the fundamental frequency contour.