Toddlers listening and learning in noise: distraction vs. signal degradation

 描述（由申请人提供）：儿童接受的输入是他们语言发展的关键因素，但他们听到的大部分语言都是针对自己和他人的，这些语言都发生在嘈杂或多人说话的环境中。然而，孩子们必须依靠这些退化的信号来尝试学习他们的母语。大脑的语言学习系统是在一个比现在安静得多的环境中进化出来的，在今天的环境中，来自交通、电视和电子设备的噪音无处不在。最近的研究表明，儿童比成人更容易受到背景噪音的影响，这可能会限制他们从语言输入中受益的程度。然而，这些与年龄相关的差异的根本原因仍然不清楚，因为这些差异实际上对学习的影响也不清楚。噪音对公众健康有重大影响，从睡眠障碍和压力到学校表现下降。噪声和其他不需要的听觉信号可能以至少两种方式潜在地影响语音处理：它们可能降低目标信号的质量（例如，通过使其部分听不见），并且它们可以用作潜在的分心或干扰源。我们预测，后者在幼儿对噪音的特殊困难中起着更大的作用，这与儿童一般的注意力发展能力有关。为了检验这一点，目前的建议有三个具体的目标：i）区分由信号退化引起的影响与分心的影响，并确定哪一个因素在儿童的感知困难中起着更大的作用，以及这与其他非语言注意技能的关系（特别是在干扰物存在下的选择性注意）;ii）调查幼儿表现出分心效应的刺激范围;以及iii）研究噪声对新单词学习的影响，而不仅仅是对已知单词的识别。区分信号衰减效应和注意力分散效应具有重要的理论和应用意义。从理论上讲，理解儿童的困难的性质提供了洞察言语知觉的机制，以及言语加工发展的性质。此外，大多数早期语言学习的理论都假设儿童在理想的听力条件下听到语言输入，或者输入已经与背景噪音分离。因此，拟议中的研究将促进语言习得更细致入微的观点的发展，并为评估和改进这些模型提供关键信息。在应用层面上，了解儿童在其他语言的背景下理解和学习口语的能力的局限性，将对儿童养育实践和理解语言延迟的潜在原因产生重要影响。这些研究的结果也将影响我们如何看待干预和儿童保育质量的影响。

 DESCRIPTION (provided by applicant): The input children receive is a critical factor in their language development, but much of the language they hear directed to themselves and others occurs in noisy or multi-talker environments. Yet children must rely on these degraded signals to attempt to learn their native language. The language learning systems of the brain evolved in what were presumably far quieter ambient environments than present-day settings, where noise from traffic, television, and electronic devices are ubiquitous. Recent work suggests that children are affected by background noise much more than are adults, potentially limiting the extent to which they can benefit from the language input they receive. Yet the underlying reason for these age-related differences remains unclear, as is the effect that such differences actually have on learning. Noise has a substantial public health impact, ranging from sleep disturbance and stress to decreased performance in school. Noise and other unwanted auditory signals can potentially affect speech processing in at least two ways: they can degrade the quality of the target signal (e.g., by making portions of it inaudible) and they can serve as a potential source o distraction or interference. We predict that the latter plays a larger role in young children's particular difficulty with noise, and that this is tied to children's developing attention abilitie in general. To examine this, the current proposal has three specific aims: i) to distinguish effects caused by the degradation of the signal from effects of distraction, and identify which factor plays the greater role in children's perceptual difficulties, and how this relates to other nonlinguistic attentional skills (specifically selective attention in the presence of distractors);ii) to investigate the range of stimuli for which young children show effects of distraction; and iii) to investigate the effects of noise on the learning of new words, not just recognition of already-known words. Distinguishing effects of signal degradation from effects of distraction has both theoretical and applied significance. Theoretically, understanding the nature of children's difficulties provides insight into the mechanisms involved in speech perception, as well as into the nature of speech processing development. Moreover, most theories of early language learning presume either that the child is hearing language input in ideal listening conditions or that the input has already been separated from background noise. The proposed studies will thus spur the development of more nuanced views of language acquisition, and provide critical information for evaluating and improving such models. On an applied level, understanding the limitations of children's ability to understand and learn from spoken language in the context of other speech will have vital implications for child-rearing practices, and for understanding potential causes for language delay. The results from these studies will also impact how we think about intervention and the effect of child care quality.