Matzinger Theresa, Ritt Nikolaus, Fitch W Tecumseh
Department of English, University of Vienna, Vienna, Austria.
Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria.
Front Psychol. 2021 Mar 16;12:622042. doi: 10.3389/fpsyg.2021.622042. eCollection 2021.
A prerequisite for spoken language learning is segmenting continuous speech into words. Amongst many possible cues to identify word boundaries, listeners can use both transitional probabilities between syllables and various prosodic cues. However, the relative importance of these cues remains unclear, and previous experiments have not directly compared the effects of contrasting multiple prosodic cues. We used artificial language learning experiments, where native German speaking participants extracted meaningless trisyllabic "words" from a continuous speech stream, to evaluate these factors. We compared a baseline condition (statistical cues only) to five test conditions, in which word-final syllables were either (a) followed by a pause, (b) lengthened, (c) shortened, (d) changed to a lower pitch, or (e) changed to a higher pitch. To evaluate robustness and generality we used three tasks varying in difficulty. Overall, pauses and final lengthening were perceived as converging with the statistical cues and facilitated speech segmentation, with pauses helping most. Final-syllable shortening hindered baseline speech segmentation, indicating that when cues conflict, prosodic cues can override statistical cues. Surprisingly, pitch cues had little effect, suggesting that duration may be more relevant for speech segmentation than pitch in our study context. We discuss our findings with regard to the contribution to speech segmentation of language-universal boundary cues vs. language-specific stress patterns.
口语学习的一个前提条件是将连续的语音分割成单词。在众多识别单词边界的可能线索中，听者既可以利用音节之间的过渡概率，也可以利用各种韵律线索。然而，这些线索的相对重要性仍不明确，而且先前的实验并未直接比较多种对比韵律线索的效果。我们采用人工语言学习实验来评估这些因素，在实验中，以德语为母语的参与者从连续的语音流中提取无意义的三音节“单词”。我们将一个基线条件（仅统计线索）与五个测试条件进行了比较，在测试条件中，词尾音节要么（a）后面跟着一个停顿，（b）被延长，（c）被缩短，（d）变为较低的音高，要么（e）变为较高的音高。为了评估稳健性和普遍性，我们使用了三个难度不同的任务。总体而言，停顿和词尾延长被认为与统计线索一致，并促进了语音分割，其中停顿的帮助最大。词尾音节缩短阻碍了基线语音分割，这表明当线索冲突时，韵律线索可以超越统计线索。令人惊讶的是，音高线索影响很小，这表明在我们的研究背景下，时长可能比音高对语音分割更重要。我们结合语言通用边界线索与特定语言重音模式对语音分割的贡献来讨论我们的研究结果。
