Same stimuli, same subjects, different perception

Believed dialect influences speech perception by linguistically naïve speakers. How much accent-induced bias affects perception of linguistically trained speakers is still unclear. This study experimentally investigates the influence of believed dialect on plosive perception by subjects who were phonetically and phonologically trained. Identical syllables were presented twice to each subject. In one session, the subjects were informed that the variety was a Mandarin dialect which has voiceless unaspirated and aspirated voiceless stops; and in the other session that it was a Wu dialect, which has voiceless unaspirated, voiceless aspirated, and breathy stops. More breathy stops were reported if Wu was the believed dialect. Plosive phonation in Wu is related to lexical tone, and we show that lexical tone causes another bias to plosive perception. This suggests that linguistically trained transcribers are susceptible to higher order linguistic knowledge and it demonstrates the difficulty of avoiding biased perception when the coder forms a belief about the variety that he/she transcribes. We also advocate speech perception models which include a component that accounts for the role of expected sounds.

在不了解语言学实验目的的情况下，人潜意识里对被感知方言的认定会影响他们的感知结果。而这种口音诱发的感知偏向多大程度上影响受过语言学训练的人则是有待研究的。本文用实验探讨受过语音学、音系学训练的标注者的方言认定对他们塞音感知的影响。相同的语音分两部分呈现给标注者。第一部分中，标注者被告知他们听到的是官话方言(具有清不送气与清送气塞音)；第二部分中，标注者被告知他们听到的是吴方言(具有清不送气，清送气与浊塞音)。结果表明，当被告知感知的是吴方言时，标注者听到更多的浊塞音。吴语中塞音类型与声调相关，我们发现声调对塞音感知也具有影响。这说明受过语言学训练的标注者易受到高层语言学知识的影响，同时也说明了一旦形成了对所标注语言的认定，他们摆脱感知偏向的困难性。我们认为言语感知模型中应引入相应的成分用来解释这种所期待的声音所起到的作用。