Sensitivity to spectral cues in infant speech perception

描述(由申请人提供)：拟议的研究将检查婴儿对言语感知中的多光谱线索的敏感性。语音是一个复杂的信号，每个辅音和元音都有许多声学提示。通过体验，听者学会利用多个线索之间的相关性，使感知更有效、更稳健。成年人通过使用光谱局部的(例如共振峰转换)和分布的(例如粗略的光谱形状或倾斜度)线索来显示这种知识，以区分语音。尽管先前的研究已经证明婴儿能够辨别许多语音，但他们是如何辨别这些声音的还不清楚。婴儿对个别线索的敏感性，他们赋予每个线索的相对重要性，以及他们何时学会利用线索之间的相关性，这些都仍然鲜为人知。我们提出了四个实验来解决这些问题。这个项目的第一个目标是研究光谱线索的敏感性。为了解决这个问题，前两个实验将检查当两个线索之间的自然协方差被破坏或保持时的语音感知。后两个实验将测试对个别线索变化的敏感度。第二个目标是评估在整个寿命中的相对线索显著程度。第一个实验的结果将与听力正常和听力受损的老年成年听众的现有数据进行比较，这些人完成了类似的任务(Alexander&Kluender，正在出版；正在准备中)，以评估听力体验和听力健康对相同言语刺激感知的不同影响。我们假设，6到7个月大的婴儿和11到12个月大的婴儿都会对言语感知中的两种光谱线索表现出感知敏感性，其中11到12个月的婴儿表现出最大的敏感性。我们还假设，与较大的婴儿相比，较小的婴儿可能相对更多地受到光谱全局(例如倾斜)线索的影响。我们的长期目标是更好地了解听力正常和听力受损婴儿的言语感知发展。这些结果将有助于完善听力损失婴儿的治疗方法，并为助听器和人工耳蜗等设备的使用提供信息。公共卫生声明：这项拟议的研究将揭示婴儿用来区分语音的声学信息，以及成年人是否以不同的方式使用这些信息。了解婴儿听的是什么，将有助于促进听力受损儿童的言语感知发展。这项研究还将调查婴儿何时学会利用自然语言中线索之间的统计规律。

DESCRIPTION (provided by applicant): The proposed research will examine infants' sensitivity to multiple spectral cues in speech perception. Speech is a complex signal, with numerous acoustic cues for every consonant and vowel. Through experience, listeners learn to exploit correlations between multiple cues, making perception more efficient and robust. Adults display this knowledge through their use of cues that are spectrally local (e.g. formant transitions) as well as distributed (e.g. gross spectral shape, or tilt) to distinguish speech sounds. Although prior research has demonstrated infants' ability to distinguish many speech sounds, how they distinguish these sounds is unclear. Infants' sensitivity to individual cues, the relative importance they assign to each cue, and when they learn to exploit correlations between cues all remain poorly understood. We propose four experiments to address these questions. The first aim of this project is to investigate sensitivity to spectral cues. To address this issue, the first two experiments will examine speech perception when the natural covariance between two cues is violated or maintained. The latter two experiments will test sensitivity to changes in individual cues. The second aim is to assess relative cue salience across the lifespan. Results from the first experiment will be compared to existing data from normal-hearing and hearing-impaired elderly adult listeners who completed a similar task (Alexander & Kluender, in press; in preparation) to assess differential effects of listening experience and hearing health on perception of the same speech stimuli. We hypothesize that both 6-to-7-month-old and 11-to-12-month-old-infants will exhibit perceptual sensitivity to both spectral cues in speech perception, with 11-to-12-month-olds displaying the greatest sensitivity. We also hypothesize that younger infants may be relatively more influenced by spectrally global (e.g. tilt) cues than older infants. Our long-term objective is to better understand development of speech perception in infants with normal and compromised hearing. These results will help refine treatment methods for infants with hearing loss, and inform the use of devices such as hearing aids and cochlear implants. Public health statement: The proposed research will reveal the acoustic information infants use to distinguish speech sounds, and whether this information is used differently by adults. Knowing what infants listen for will benefit efforts to facilitate development of speech perception in children with compromised hearing. This research will also investigate when infants learn to exploit statistical regularities between cues in natural speech.