Hawthorne Kara
Department of Communication Sciences and Disorders, University of Mississippi, 304 George Hall, University, Mississippi 38677, USA.
J Acoust Soc Am. 2018 May;143(5):2756. doi: 10.1121/1.5031130.
Across languages, prosodic boundaries tend to align with syntactic boundaries, and both infant and adult language learners capitalize on these correlations to jump-start syntax acquisition. However, it is unclear which prosodic cues-pauses, final-syllable lengthening, and/or pitch resets across boundaries-are necessary for prosodic bootstrapping to occur. It is also unknown how syntax acquisition is impacted when listeners do not have access to the full range of prosodic or spectral information. These questions were addressed using 14-channel noise-vocoded (spectrally degraded) speech. While pre-boundary lengthening and pauses are well-transmitted through noise-vocoded speech, pitch is not; overall intelligibility is also decreased. In two artificial grammar experiments, adult native English speakers showed a similar ability to use English-like prosody to bootstrap unfamiliar syntactic structures from degraded speech and natural, unmanipulated speech. Contrary to previous findings that listeners may require pitch resets and final lengthening to co-occur if no pause cue is present, participants in the degraded speech conditions were able to detect prosodic boundaries from lengthening alone. Results suggest that pitch is not necessary for adult English speakers to perceive prosodic boundaries associated with syntactic structures, and that prosodic bootstrapping is robust to degraded spectral information.
在各种语言中，韵律边界往往与句法边界对齐，婴儿和成人语言学习者都利用这些关联来启动句法习得。然而，尚不清楚哪些韵律线索——边界处的停顿、音节末延长和/或音高重置——对于韵律引导的发生是必要的。当听众无法获取完整的韵律或频谱信息时，句法习得如何受到影响也不清楚。这些问题通过14通道噪声声码（频谱退化）语音进行了研究。虽然边界前延长和停顿在噪声声码语音中能很好地传递，但音高却不能；整体可懂度也会降低。在两项人工语法实验中，成年英语母语者表现出类似的能力，即利用类似英语的韵律从退化语音和自然、未处理的语音中引导出不熟悉的句法结构。与之前的研究结果相反，即如果没有停顿线索，听众可能需要音高重置和音节末延长同时出现，在退化语音条件下的参与者仅通过延长就能检测到韵律边界。结果表明，对于成年英语使用者来说，音高对于感知与句法结构相关的韵律边界并非必要，并且韵律引导对退化的频谱信息具有鲁棒性。
