Perception in complex, multi-source environments

描述：听力受损的听者和人工耳蜗使用者在有多个竞争声源的环境中很难选择性地注意到一个声源。相比之下，听力正常的听众能够有选择地在众多的竞争来源中关注感兴趣的说话者，并根据需要转移注意力。该项目的长期目标是开发策略和设备，帮助受损听众在需要选择性注意力的日常社会环境中有效沟通。目前的建议是建立在这样一个假设之上的，即受损的听者在复杂环境中遇到的一些困难源于正确形成听觉“对象”的困难（即，将来自一个物理来源的声音分组成一个单一的感知实体）。由于听觉分组和听觉感知之间的相互作用尚不清楚，因此实现我们长期目标的必要的第一步是了解将声音分组为物体如何影响正常听力听众的感知。我们将在正常听力的听众中进行心理物理实验，测试分组如何影响听觉感知，并使用计算模型来理解通常影响听众在竞争声源混合中如何注意一个声源的过程。本项目的具体目的是探讨感知分组如何影响对基本心理物理声音属性的感知敏感性（目标1和2），以及当存在竞争的类似声源时理解言语的能力（目标3）。目标1探讨了当音调被感知地整合到包含其他声音的物体中时，对空间线索的敏感性和音调的强度是如何降低的。目标2探索了当竞争声音干扰目标音调的感知分组时，如何提取由多个同时或顺序的目标音调（例如，光谱轮廓，节奏，音高轮廓）定义的光谱时间模式的能力可能会降低。目标3测量在存在竞争性声音物体的情况下，减弱的分组线索（如听力障碍或通过人工耳蜗植入的常见线索）如何干扰语音清晰度。总之，拟议的研究测试了一个统一的概念模型，即为什么感知分组直接影响在复杂的社会环境中的沟通能力，从激烈的商务会议到热闹的晚宴。助听器和人工耳蜗使用者最常见的抱怨之一是，他们无法在有多个相互竞争的声源的日常环境中有效沟通。这个问题通常会导致社会孤立，因为听众选择不去尝试参与复杂的环境，而不是面对挫折和失败。了解正常听者应对复杂声学环境的过程是开发信号处理方案和设备以改善受损听者所面临的困难的关键和必要步骤。

DESCRIPTION: Hearing-impaired listeners and cochlear implant users have difficulty selectively attending to a sound source in environments with multiple, competing sound sources. In contrast, normal-hearing listeners are able to selectively attend to a talker of interest in a sea of competing sources, shifting attention as the need arises. The long-term objective of this project is to develop strategies and devices to help impaired listeners communicate effectively in everyday social settings that require selective attention. The current proposal is built on the hypothesis that some of the difficulty that impaired listeners have in complex environments stems from difficulties in properly forming auditory "objects" (i.e., grouping sound coming from one physical source into a single perceptual entity). Because interactions between auditory grouping and auditory perception are poorly understood, a necessary first step towards our long-term objective is to understand how the grouping of sound into objects affects perception in normal-hearing listeners. We will perform psychophysical experiments in normal- hearing listeners that test how grouping influences auditory perception and use computational models to understand the processes that normally affect how listeners attend to one source in a mixture of competing sound sources. The specific aims of this project explore how perceptual grouping influences perceptual sensitivity to basic psychophysical sound attributes (Aims 1 and 2) as well as the ability to understand speech when there is a competing, similar sound source (Aim 3). Aim 1 explores how sensitivity to spatial cues and the intensity of one tone can be degraded when that tone is perceptually integrated into an object containing other sounds. Aim 2 explores how the ability to extract the spectro-temporal pattern defined by multiple simultaneous or sequential target tones (e.g., spectral profile, rhythm, pitch contour) can be degraded when competing sounds interfere with the perceptual grouping of the target tones into a perceptual object. Aim 3 measures how weakened grouping cues (like those commonly experienced with hearing impairment or through a cochlear implant) interfere with speech intelligibility in the presence of a competing sound object. Together, the proposed studies test a unified conceptual model of why perceptual grouping directly influences the ability to communicate in the complex social settings, from heated business meetings to lively dinner parties. PUBLIC HEALTH RELEVANCE One of the most common complaints of hearing aid and cochlear implant users is that they cannot communicate effectively in everyday settings where there are multiple, competing sound sources. This problem often causes social isolation, as listeners opt out of trying to participate in complex settings rather than facing frustration and failure. Understanding the processes that allow normal- hearing listeners to cope with complex acoustic environments is a critical and necessary step towards developing signal-processing schemes and devices to ameliorate the difficulties facing impaired listeners.