Heffner Christopher C, Newman Rochelle S, Idsardi William J
Program in Neuroscience and Cognitive Science, University of Maryland, 1401 Marie Mount Hall, 7814 Regents Dr., College Park, MD, 20742, USA.
Department of Hearing and Speech Sciences, University of Maryland, College Park, MD, 20742, USA.
Atten Percept Psychophys. 2017 Apr;79(3):964-988. doi: 10.3758/s13414-016-1274-5.
Listeners must adapt to differences in speech rate across talkers and situations. Speech rate adaptation effects are strong for adjacent syllables (i.e., proximal syllables). For studies that have assessed adaptation effects on speech rate information more than one syllable removed from a point of ambiguity in speech (i.e., distal syllables), the difference in strength between different types of ambiguity is stark. Studies of word segmentation have shown large shifts in perception as a result of distal rate manipulations, while studies of segmental perception have shown only weak, or even nonexistent, effects. However, no study has standardized methods and materials to study context effects for both types of ambiguity simultaneously. Here, a set of sentences was created that differed as minimally as possible except for whether the sentences were ambiguous to the voicing of a consonant or ambiguous to the location of a word boundary. The sentences were then rate-modified to slow down the distal context speech rate to various extents, dependent on three different definitions of distal context that were adapted from previous experiments, along with a manipulation of proximal context to assess whether proximal effects were comparable across ambiguity types. The results indicate that the definition of distal influenced the extent of distal rate effects strongly for both segments and segmentation. They also establish the presence of distal rate effects on word-final segments for the first time. These results were replicated, with some caveats regarding the perception of individual segments, in an Internet-based sample recruited from Mechanical Turk.
听众必须适应不同说话者和不同情境下语速的差异。语速适应效应在相邻音节（即近端音节）上表现强烈。对于那些评估在语音中从歧义点起超过一个音节的语速信息的适应效应的研究（即远端音节），不同类型歧义之间强度的差异非常明显。词切分研究表明，由于远端语速操纵，感知上会有很大变化，而音段感知研究则表明影响微弱，甚至不存在影响。然而，尚无研究同时针对这两种歧义类型，采用标准化方法和材料来研究语境效应。在此，创建了一组句子，这些句子除了在辅音发音是否歧义或词边界位置是否歧义方面存在差异外，其他方面尽可能保持最小差异。然后根据从先前实验改编的三种不同远端语境定义，对句子进行语速调整，以不同程度减缓远端语境语速，同时对近端语境进行操纵，以评估近端效应在不同歧义类型之间是否具有可比性。结果表明，远端的定义对音段和切分的远端语速效应程度有强烈影响。研究还首次证实了词尾音段存在远端语速效应。在从亚马逊土耳其机器人招募的基于互联网的样本中，这些结果得到了重复，但在个别音段的感知方面存在一些限制条件。
