Smiljanić Rajka, Bradlow Ann R
Department of Linguistics, Northwestern University, Evanston, Illinois 60208, USA.
J Acoust Soc Am. 2008 Nov;124(5):3171-82. doi: 10.1121/1.2990712.
This study investigated the effect of hyperarticulated, intelligibility-enhancing clear speech on temporal characteristics as reflected in number, durations, and variability of consonant and vowel intervals in sentence- and paragraph-length utterances. The results of sentence-in-noise listening tests showed a consistent clear speech intelligibility gain across the utterances of varying complexity indicating that the talkers successfully maintained clear speech articulatory modifications throughout longer stretches of speech. The acoustic analysis revealed that some temporal restructuring accompanied changes in speaking style. This temporal restructuring was observed in the insertion of consonant and vowel segments that were dropped or coarticulated in conversational speech and in an increase in the number of prosodic phrases for clear speech. Importantly, coefficients of variation (variation of consonantal and vocalic intervals normalized for changes in speaking rate) for both consonantal and vowel intervals remained stable in the two speaking styles. Overall, these results suggest that increased intelligibility of clear speech may be attributed to prosodic structure enhancement (increased phrasing and enhanced segmentability) and stable global temporal properties.
本研究调查了超清晰、增强可懂度的清晰言语对句子和段落长度话语中辅音和元音间隔的数量、时长及变异性所反映的时间特征的影响。噪声环境下句子听力测试结果显示，在不同复杂程度的话语中，清晰言语的可懂度持续提高，这表明说话者在较长的言语片段中成功保持了清晰言语的发音调整。声学分析表明，言语风格的变化伴随着一些时间结构的调整。这种时间结构调整表现为在对话言语中被省略或协同发音的辅音和元音片段的插入，以及清晰言语中韵律短语数量的增加。重要的是，两种言语风格中辅音和元音间隔的变异系数（针对语速变化进行归一化处理的辅音和元音间隔变异）均保持稳定。总体而言，这些结果表明，清晰言语可懂度的提高可能归因于韵律结构的增强（增加了断句和提高了可分割性）以及稳定的整体时间特性。
