Exploring the onset of phonetic drift in voice onset time perception

Recent exposure to a second or foreign language (FL) can influence production and/or perception in the first language (L1), a phenomenon referred to as phonetic drift. The smallest amount of FL exposure shown to effect drift in perception is 1.5 hours (Gong et al. 2016). The present study examined L1 perception at earlier timepoints of FL exposure, to determine whether the phonetic system is able to resist FL influence at an incipient stage. In a longitudinal pre-test/post-test design, L1 English listeners were exposed to Tagalog under different conditions varying in attention directed to the voice onset time (VOT) plosive contrast in the FL; they then completed an identification task on L1 tokens from VOT continua. In every condition the likelihood of “voiceless” identifications decreased. This change indicates a shift towards a longer VOT crossover point between “voiced” and “voiceless”, consistent with dissimilatory drift in perception. Listeners in a control condition, however, displayed a similar, albeit less lasting, change in L1 judgments, suggesting that the change arose partly from a task effect. We conclude by discussing directions for future research on phonetic drift in perception.

近期接触第二语言或外语（FL）可对第一语言（L1）的产出与/或感知产生影响，此现象被称为语音漂移。据 Gong 等人（2016年）研究显示，FL 接触量最少为 1.5 小时即可引起感知上的漂移。本研究旨在考察 FL 接触的早期阶段对 L1 感知的影响，以确定语音系统是否能够在萌芽阶段抵御 FL 的影响。在纵向的前测/后测设计中，L1 英语听者在不同条件下接触 Tagalog，这些条件在 FL 中声母发音时间（VOT）爆破对比的注意力分配上有所差异；随后，他们对来自 VOT 演续的 L1 Token 进行了识别任务。在所有条件下，“清音”识别的可能性均有所降低。这一变化表明，感知上出现了向“浊音”与“清音”之间更长的 VOT 交叉点的转变，这与感知上的异化漂移一致。然而，在控制条件下，听者表现出相似但持续时间较短的 L1 判断变化，这表明这种变化部分源于任务效应。我们最后讨论了未来研究语音感知中语音漂移的方向。