Factors that facilitate perception of degraded speech and speech in noise

在日常生活中，我们经常会在说话者或其他噪音的干扰下听到讲话。如果背景声音足够强烈，目标语音就会被有效地降级，变得难以理解，以至于即使是最复杂的自动语音识别系统也会在很大程度上失败。然而，正常听力的人类听者在类似水平的背景噪音下能明显（欺骗性）轻松地理解讲话。人类善于利用自己的知识和经验来帮助他们解读模棱两可的语音信号。特别是，有意义的语义语境有助于年轻人和老年人理解口语句子，特别是在听力困难的情况下。虽然这项研究有很长的历史，但我们对语境效应的理解——它们何时出现以及它们影响理解的机制——是有限的。这里提出的工作将探索当语音难以理解时，约束信息（即有意义的上下文）如何促进理解，或者因为它以某种方式被削弱（例如，因为对话者有很强的口音或语音通过人工耳蜗转导），或者因为它部分被背景声音掩盖。这项工作将从根本上为语言感知中的语境效应的理论解释做出贡献。这一点很重要，因为理解噪音中的言语是老年人最常见的抱怨之一，迄今为止的研究都集中在解释这个问题（与年龄有关的听力和认知变化），从本质上讲，这是不容易补救的。我的实验室的研究是非常规的，它关注的是促进成功感知语言的因素，以及可能减轻听力损失影响的因素。其中最重要的一点是有效地使用有意义的语境。随着人们年龄的增长和处理声音输入的保真度的下降，这种基于知识的语音理解线索变得越来越重要。更全面地了解能够促进言语理解的因素有助于优化它们并促进它们的使用。

In everyday life, speech is often heard against a background of interfering talkers or other noise. If the background sound is sufficiently intense, target speech is effectively degraded and becomes hard to understand, to the point that even the most sophisticated automatic speech recognition systems will largely fail. Nevertheless, normally hearing human listeners presented with similar levels of background noise understand speech with apparent (deceptive) ease. Humans are adept at using their knowledge and experience to help them interpret an ambiguous speech signal. In particular, meaningful semantic context facilitates comprehension of spoken sentences by young and older adults, especially in difficult listening conditions. Although this research has a long history, our understanding of contextual effects -- when they arise and the mechanisms by which they influence comprehension -- are limited. The work proposed here will explore how constraining information (i.e., meaningful context) facilitates comprehension when speech is difficult to understand, either because it is degraded in some way (e.g., because the interlocutor has a strong accent or the speech is transduced through a cochlear implant) or because it is partially masked by background sounds. This work will contribute fundamentally to a theoretical account of contextual effects in speech perception. This is important because understanding speech in noise is one of the most common complaints of older individuals, and research to date has focused on explanations of the problem (age-related changes in hearing and cognition) that, by their nature, are not easily remediable. Research in my lab is unconventional in its focus on factors that facilitate successful perception of speech and which may act to mitigate the effects of hearing loss. One of the most important of these is the effective use of meaningful context. As people age and the fidelity with which acoustic input is processed deteriorates, such knowledge-based cues to speech comprehension become increasingly important. A more complete understanding of the factors that can facilitate speech comprehension is instrumental to optimizing them and promoting their use.