Our study proposes the use of a free classification task for investigating the dimensions used by listeners in their perception of nonnative sounds and for predicting the perceptual discriminability of nonnative contrasts. In a free classification task, participants freely group auditory stimuli based on their perceived similarity. The results can be used to predict discriminability and can be compared to various acoustic or phonological dimensions to determine the relevant cues for listeners. The viability of this method was examined for both a segmental contrast (German vowels) and a nonsegmental contrast (Finnish phonemic length). Perceptual similarity data from the free classification task accurately predicted discriminability in an oddity task and separately provided rich information on how the perceptual space is shaped. These results suggest that a free classification task and related analyses are informative and replicable methods for examining nonnative speech perception.

我们的研究建议使用免费分类任务来调查听众在感知非母语声音时使用的维度，并预测非母语对比的感知辨别能力。在自由分类任务中，参与者根据感知的相似性对听觉刺激进行自由分组。结果可用于预测可辨别性，并可与各种声学或语音维度进行比较，以确定听众的相关线索。对该方法的可行性进行了分段对比（德语元音）和非分段对比（芬兰语音素长度）的检验。来自自由分类任务的感知相似性数据准确地预测了奇怪任务中的可辨别性，并分别提供了有关感知空间如何形成的丰富信息。这些结果表明，自由分类任务和相关分析是检查非母语语音感知的信息丰富且可复制的方法。