The development of phonetic perception

这个研究项目通过对元音感知的调查来探索婴儿期言语感知的发展。我们的目标是充分描绘元音知觉偏见，幼儿显示在回应讲话，解释如何以及何时这些知觉偏见形成的发展，并建立他们在口语习得的作用。 在追求这些目标，我们将测试和阐述一个新的概念模型，自然参照元音（NRV）框架。 根据这一观点，具有特定发音声学特性的元音（也定义了传统元音空间中的周边元音）充当自然的参照物：它们通过吸引婴儿的注意力和为学习者建立稳定的参照系来支持和引导元音感知的发展。 先前的研究表明，婴儿（4至12个月大）有一个强烈的知觉偏向，有利于周边元音的不同元音的婴儿听力偏好支持这一观点。 研究1将评估这种感知偏差何时（以及如何）在婴儿早期形成。 我们将比较2个月大的婴儿和新生儿，以评估元音感知偏差在生命早期通过婴儿神经听觉能力和言语暴露之间的相互作用而出现的假设。 研究2和3将测试NRV声称，周边元音支持元音感知和生产的发展。 研究2测试的预测，元音感知偏差也影响婴儿如何感知自己的声音模式，通过检查婴儿听力偏好的元音产生的婴儿说话（使用一种新的元音合成工具）。 研究3将评估婴儿识别不同说话者（成人、儿童、婴儿）发出的相同元音的能力，以测试NRV预测，即元音分类技能以逐步、分层的方式发展，使得周边元音类别更容易获得，并且先于非周边元音类别。 这将是第一个研究婴儿如何感知婴儿发出的声音信号的研究。 这种方法是需要了解如何说话和听力技能互动在婴儿言语发展。

This research program explores the development of speech perception in infancy through investigations that focus on vowel perception. Our goal is to fully portray vowel perception biases that young infants display in response to speech, explain how and when these perceptual biases form in development, and establish their role in the acquisition of spoken language. In pursuing these goals we will test and elaborate a new conceptual model, the Natural Referent Vowel (NRV) framework. According to this view, vowels with specific articulatory-acoustic properties (which also define the peripheral vowels in a traditional vowel space) act a natural referents: they support and guide the development of vowel perception by attracting infant attention and establishing a stable frame of reference for the learner. Prior studies of infant listening preferences for different vowels support this view by showing that infants (4 to 12 months of age) have a strong perceptual bias favoring peripheral vowels. Study 1 will assess when (and how) this perceptual bias is initially formed in early infancy. We will compare 2-month-olds and newborns to assess the hypothesis that vowel perception biases emerge early in life via an interaction between infant neuro-auditory abilities and speech exposure. Studies 2 and 3 will test the NRV claim that peripheral vowels support the development of vowel perception and production. Study 2 tests the prediction that vowel perception biases also impact how babies perceive their own vocal patterns by examining infant listening preferences for vowels produced by an infant talker (using a new vowel synthesis tool). Study 3 will assess infant ability to recognize the same vowel produced by different talkers (adult, child, infant) to test the NRV prediction that vowel categorization skills develop in a stepwise, hierarchical manner such that peripheral vowel categories are acquired more easily and prior to non-peripheral vowel categories. This will be the first study to investigate how infants perceive infant-produced vocal signals. This approach is needed to understand how speaking and listening skills interact in infant speech development.