Edwards J, Beckman M E, Fletcher J
Communication Sciences Program, Hunter School of Health Sciences, Hunter College, City University of New York, New York 10010.
J Acoust Soc Am. 1991 Jan;89(1):369-82. doi: 10.1121/1.400674.
In order to understand better the phonetic control of final lengthening, the articulation of phrase-final syllables was compared with that of two other contexts known to increase syllable duration: accent and slow tempo. The kinematics of jaw movements in [pap] sequences and of lower lip movements in [pe] sequences for four subjects were interpreted in terms of a task-dynamic model. There was evidence of two different control strategies: decreasing intragestural stiffness to slow down some part of the syllable, and changing intergestural phasing to decrease overlap of the vowel gesture by the consonant. The first was used in slowing down tempo, whereas the second was used to increase the duration of accented syllables over unaccented syllables. Both strategies were implicated in phrase-final lengthening. In accented syllables, final closing gestures generally were longer and slower, but not more displaced. The two slowest subjects, however, used the other strategy in their slow-tempo final syllables. Final lengthening in reduced syllables was more difficult to interpret. The relationship between peak velocity and displacement suggested that a lesser stiffness is obscured by an increased gestural amplitude. Thus, by comparison to lengthening for accent, final lengthening is like a localized change in speaking tempo, although it cannot be equated directly with the specification of stiffness.
为了更好地理解词尾延长的语音控制，将短语末尾音节的发音与已知会增加音节时长的其他两种语境下的发音进行了比较：重音和慢节奏。根据任务动态模型对四名受试者在 [pap] 序列中的下颌运动和 [pe] 序列中的下唇运动的运动学进行了解释。有证据表明存在两种不同的控制策略：降低手势内的刚度以减缓音节的某些部分，以及改变手势间的相位以减少辅音对元音手势的重叠。第一种策略用于减慢节奏，而第二种策略用于增加重读音节相对于非重读音节的时长。两种策略都与短语末尾延长有关。在重读音节中，最后的闭合手势通常更长、更慢，但位移并不更大。然而，两名语速最慢的受试者在他们慢节奏的末尾音节中使用了另一种策略。弱化音节中的词尾延长更难解释。峰值速度与位移之间的关系表明，较小的刚度被增加的手势幅度所掩盖。因此，与重音延长相比，词尾延长就像是说话节奏的局部变化，尽管它不能直接等同于刚度的设定。
