Sjerps Matthias J, McQueen James M, Mitterer Holger
Max Planck Institute for Psycholinguistics, Wundtlaan 1, 6525 XD Nijmegen, The Netherlands.
Atten Percept Psychophys. 2013 Apr;75(3):576-87. doi: 10.3758/s13414-012-0408-7.
Three experiments investigated whether extrinsic vowel normalization takes place largely at a categorical or a precategorical level of processing. Traditional vowel normalization effects in categorization were replicated in Experiment 1: Vowels taken from an [I]-[ε] continuum were more often interpreted as /I/ (which has a low first formant, F(1)) when the vowels were heard in contexts that had a raised F(1) than when the contexts had a lowered F(1). This was established with contexts that consisted of only two syllables. These short contexts were necessary for Experiment 2, a discrimination task that encouraged listeners to focus on the perceptual properties of vowels at a precategorical level. Vowel normalization was again found: Ambiguous vowels were more easily discriminated from an endpoint [ε] than from an endpoint [I] in a high-F(1) context, whereas the opposite was true in a low-F(1) context. Experiment 3 measured discriminability between pairs of steps along the [I]-[ε] continuum. Contextual influences were again found, but without discrimination peaks, contrary to what was predicted from the same participants' categorization behavior. Extrinsic vowel normalization therefore appears to be a process that takes place at least in part at a precategorical processing level.
三项实验探究了外在元音归一化主要是在分类水平还是在分类前水平的加工过程中发生。实验1重复了分类中传统的元音归一化效应：当在第一共振峰（F(1)）升高的语境中听到从[I]-[ε]连续体中选取的元音时，相比于在F(1)降低的语境中听到这些元音，它们更常被解释为/I/（其具有较低的第一共振峰F(1)）。这是通过仅由两个音节组成的语境得以证实的。这些简短的语境对于实验2是必要的，实验2是一项辨别任务，鼓励听众在分类前水平关注元音的感知属性。再次发现了元音归一化现象：在高F(1)语境中，模糊元音与端点[ε]相比，比与端点[I]更容易区分，而在低F(1)语境中情况则相反。实验3测量了沿着[I]-[ε]连续体的成对音步之间的可辨别性。再次发现了语境影响，但没有辨别峰值，这与从相同参与者的分类行为所预测的情况相反。因此，外在元音归一化似乎是一个至少部分在分类前加工水平发生的过程。
