Sensitivity to spectral cues in infant speech perception

描述（由申请人提供）：拟进行的研究将研究婴儿在言语感知中对多谱线索的敏感性。语音是一个复杂的信号，每个辅音和元音都有大量的声学线索。通过经验，听众学会利用多个线索之间的相关性，使感知更有效、更稳健。成年人通过使用频谱局部（如波峰转换）和分布（如总频谱形状或倾斜）的线索来区分语音来展示这种知识。虽然先前的研究已经证明婴儿有能力区分许多语音，但他们是如何区分这些声音的还不清楚。婴儿对单个线索的敏感性，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，这些都尚不清楚。我们提出了四个实验来解决这些问题。该项目的第一个目的是研究对光谱线索的敏感性。为了解决这个问题，前两个实验将研究当两个线索之间的自然协方差被破坏或维持时的语音感知。后两个实验将测试个体对线索变化的敏感度。第二个目的是评估整个生命周期的相对线索显著性。第一个实验的结果将与完成类似任务的正常听力和听力受损老年听众的现有数据进行比较（Alexander & Kluender, in press; in preparation），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- 7个月大和11- 12个月大的婴儿在言语感知中对两种光谱线索都表现出感知敏感性，其中11- 12个月大的婴儿表现出最大的敏感性。我们还假设年幼的婴儿可能比年长的婴儿更容易受到光谱全球（例如倾斜）线索的影响。我们的长期目标是更好地了解正常和受损听力婴儿的语言感知发展。这些结果将有助于改进婴儿听力损失的治疗方法，并为使用助听器和人工耳蜗等设备提供信息。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，以及成年人是否会以不同的方式使用这些信息。了解婴儿在听什么将有助于促进听力受损儿童语言感知的发展。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.