Neural Correlates of Streaming of Complex Sounds

项目摘要 这项研究的目的是解释听觉系统如何分析复杂的 声学场景，其中多个声音“流”（例如，并发语音）交互 争夺注意力协同效应是通过以下方式产生的：1）同时的行为 雪貂初级和次级听觉皮层的神经生理学测量 与2）行为和脑电图（EEG）测量结果相当， 3）时间的理论和计算框架内的人类 连贯性假说具体目标1涉及记录单个单位皮质 当雪貂分离语音混合物并检测目标的存在时， 目标说话人说的话。这些实验将通过人体试验来验证。 由浊音（谐波）的自然混合组成的语音声音的流 和无声的（类似噪音的）声音。具体目标2探讨了一致性的作用， 使用具有更简单频谱的刺激的流绑定和分离中的注意 特征，例如，纯音和噪声序列。我们的目标是测试强大 时间相干性假设的预测 时间上同步的、交替的或重叠的声音序列。具体目标3 将这种方法扩展到更复杂刺激的更高级别属性，例如音高 和音色，这些都是更生态相关的。在这里，我们研究了音高的作用， 音色在表征流的连续性，并结合的元素， 雪貂和人类体内都有。这项研究具有直接和重大的健康 影响，因为听力受损的最常见的投诉之一 个人（包括助听器或人工耳蜗植入物的佩戴者），他们发现它 很难区分并发的声音流，并有选择地注意其中之一， 这些流（如某人的声音）在其他流中。更清楚 理解感知分离能力的机制，以及 注意，听觉流可能会导致更清楚地了解 这些选择性倾听的困难，它可能会激发设计更有效的 用于助听器、耳蜗植入物和自动 语音识别设备。

Project Summary The goal of this research is to explain how the auditory system analyzes complex acoustic scenes, in which multiple sound “streams” (e.g., concurrent voices) interact and compete for attention. Synergy is created by combining 1) simultaneous behavioral and neurophysiological measures from primary and secondary auditory cortex in ferrets with 2) comparable behavioral and electroencephalographic (EEG) measures in humans within 3) the theoretical and computational framework of the temporal coherence hypothesis. Specific Aim 1 involves recordings of single-unit cortical responses while ferrets segregate speech mixtures and detect the presence of a target word spoken by the target talker. The experiments will be paralleled by tests of human streaming of speech sounds that are comprised of natural mixtures of voiced (harmonic) and unvoiced (noise-like) sounds. Specific Aim 2 explores the role of coherence and attention in stream binding and segregation using stimuli with simpler spectral characteristics, e.g., pure-tones and noise sequences. The goal is to test strong predictions of the temporal coherence hypothesis with respect to the effects of temporally synchronous, alternating, or overlapping sound sequences. Specific Aim 3 extends this approach to higher-level attributes of more complex stimuli, such as pitch and timbre, which are more ecologically relevant. Here we examine the role of pitch and timbre in characterizing the continuity of a stream, and binding the elements of the stream in both ferrets and humans. This research has direct and significant health implications, because one of the most common complaints of hearing-impaired individuals (including wearers of hearing aids or cochlear implants) is that they find it difficult to separate concurrent streams of sounds, and to attend selectively to one of these streams (such as someone's voice) among other streams. A clearer understanding of the mechanisms underlying the perceptual ability to separate, and attend to, auditory streams will likely lead to a clearer understanding of the origin of these selective-listening difficulties, and it may inspire the design of more effective sound-separation algorithms for use in hearing aids, cochlear implants, and automatic speech recognition devices.