The perceptual organization of speech: Contributions of general and speech-specific factors

口语交流是一项基本的人类活动。然而，在日常生活中，我们很少在没有其他背景声音的情况下听到一个说话人的讲话，因此我们的听觉系统面临着将来自一个来源的声音元素组合在一起并将它们与来自其他来源的声音元素分开的挑战。如果不解决这个听觉场景分析问题，我们对言语和其他声音的感知就不会与产生它们的事件相对应。事实上，我们可以将注意力集中在一个说话的人身上，而在场的还有其他说话的人，这表明我们的听觉感知系统通常能够成功地将来自复杂听觉场景中某个声源的声音元素组合在一起，并将它们与其他声源分离开来，但我们对如何实现这一目标的理解仍然有限。大多数关于听觉场景分析的研究都集中在相对简单的声音上，并已经确定了一些声音元素分组的一般原则。然而，至少就目前所知，这些原则似乎不足以解释语音的感知分组，因为语音具有多种多样且快速变化的声学特性。此外，言语是一种高度熟悉的刺激，因此我们的听觉系统有机会学习言语的特定属性，这可能有助于成功地对言语进行感知分组。这个项目的目的是探索我们将说话者的语音从混合声音中分离出来的能力，在多大程度上取决于适用于所有声音的通用听觉分组原则，以及在多大程度上取决于特定于语音的分组原则。该方法是产生具有精确控制特性的人工类语音刺激，将目标话语与精心设计的竞争对手混合在一起，提供不同的分组可能性，并测量操纵这些竞争对手的声学特性如何影响听者在混合物中识别目标话语的能力。该项目的结果将提高我们对语音感知组织的理解，并为提高助听器和自动语音识别器等设备在嘈杂环境中工作时的性能提供方法。

Spoken communication is a fundamental human activity. However, it is fairly uncommon in everyday life for us to hear the speech of a single talker in the absence of other background sounds, and so our auditory system is faced with the challenge of grouping together those sound elements that come from one source and segregating them from those arising from other sources. Without a solution to this auditory scene analysis problem, our perceptions of speech and other sounds would not correspond to the events that produced them. The fact that we can focus our attention on one person speaking in the presence of other talkers indicates that our auditory perceptual system is generally successful at grouping together the sound elements from a source in a complex auditory scene, and segregating them from other sound sources, but our understanding of how this is achieved remains limited. Most research on auditory scene analysis has focused on relatively simple sounds and has identified a number of general principles for the grouping of sound elements. However, at least as currently understood, these principles seem inadequate to explain the perceptual grouping of speech, because speech has acoustic properties that are diverse and rapidly changing. Furthermore, speech is a highly familiar stimulus, and so our auditory system has had the opportunity to learn about speech-specific properties that may assist in the successful perceptual grouping of speech. The aim of this project is to explore how much of our ability to segregate a talker's speech from a sound mixture depends on general-purpose auditory grouping principles that are applicable to all sounds, and how much depends on grouping principles that are specific to speech sounds. The approach is to generate artificial speech-like stimuli with precisely controlled properties, to mix target utterances with carefully designed competitors that offer alternative grouping possibilities, and to measure how manipulating the acoustic properties of these competitors affects the ability of listeners to recognize the target utterance in the mixture. The results of this project will improve our understanding of the perceptual organization of speech and suggest ways to improve the performance of devices such as hearing aids and automatic speech recognizers when they are operating in noisy environments.