Viswanathan Navin, Magnuson James S, Fowler Carol A
Department of Psychology, State University of New York.
Department of Psychology, The University of Connecticut.
J Exp Psychol Hum Percept Perform. 2014 Jun;40(3):1228-36. doi: 10.1037/a0036214. Epub 2014 Apr 14.
Perception of a speech segment changes depending on properties of surrounding segments in a phenomenon called compensation for coarticulation (Mann, 1980). The nature of information that drives these perceptual changes is a matter of debate. One account attributes perceptual shifts to low-level auditory system contrast effects based on static portions of the signal (e.g., third formant [F3] center or average frequency; Lotto & Kluender, 1998). An alternative account is that listeners' perceptual shifts result from listeners attuning to the acoustic effects of gestural overlap and that this information for coarticulation is necessarily dynamic (Fowler, 2006). In a pair of experiments, we used sinewave speech precursors to investigate the nature of information for compensation for coarticulation. In Experiment 1, as expected by both accounts, we found that sinewave speech precursors produce shifts in following segments. In Experiment 2, we investigated whether effects in Experiment 1 were driven by static F3 offsets of sinewave speech precursors, or by dynamic relationships among their formants. We temporally reversed F1 and F2 in sinewave precursors, preserving static F3 offset and average F1, F2 and F3 frequencies, but disrupting dynamic formant relationships. Despite having identical F3s, selectively reversed precursors produced effects that were significantly smaller and restricted to only a small portion of the continuum. We conclude that dynamic formant relations rather than static properties of the precursor provide information for compensation for coarticulation.
在一种被称为协同发音补偿的现象中，对语音片段的感知会根据周围片段的属性而发生变化（曼恩，1980年）。驱动这些感知变化的信息的本质是一个有争议的问题。一种观点认为，感知变化归因于基于信号静态部分的低水平听觉系统对比效应（例如，第三共振峰[F3]中心或平均频率；洛托和克伦德，1998年）。另一种观点是，听众的感知变化是由于听众适应了手势重叠的声学效应，并且这种协同发音的信息必然是动态的（福勒，2006年）。在一对实验中，我们使用正弦波语音前体来研究协同发音补偿的信息本质。在实验1中，正如两种观点所预期的，我们发现正弦波语音前体会在后续片段中产生变化。在实验2中，我们研究了实验1中的效应是由正弦波语音前体的静态F3偏移驱动的，还是由它们的共振峰之间的动态关系驱动的。我们在正弦波前体中对F1和F2进行了时间反转，保留了静态F3偏移以及平均F1、F2和F3频率，但破坏了动态共振峰关系。尽管具有相同的F3，但选择性反转的前体产生的效应明显较小，并且仅限于连续体的一小部分。我们得出结论，前体的动态共振峰关系而非静态属性为协同发音补偿提供了信息。
