Cortical processing of informational masking

信息掩蔽的皮质处理

• 批准号: 10097727
• 负责人: Antje Ihlefeld
• 金额: $ 30.87万
• 依托单位: NEW JERSEY INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-18 至 2021-08-20
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10097727
• 关键词: Acoustic Nerve; Active Listening; Affect; Animal Model; Animals; Auditory; Auditory area; Base of the Brain; Behavioral; Blood; Brain; Cochlear Implants; Communication; Conductive hearing loss; Data; Development; Employment; Environment; Frequencies; Gerbils; Goals; Hearing; Hearing Aids; Hearing Tests; Human; Individual; Jird; Lead; Link; Masks; Measures; Mental Depression; Modeling; Near-Infrared Spectroscopy; Nerve Fibers; Neurons; Performance; Persons; Phenotype; Physiology; Positioning Attribute; Predisposition; Psychophysics; Quality of life; Rehabilitation therapy; Sensory; Social isolation; Speech; Speech Intelligibility; Techniques; Testing; Time; Training; Uncertainty; Variant; Work; Workplace; auditory deprivation; auditory pathway; auditory processing; base; behavioral outcome; clinically relevant; combat; experimental study; hearing impairment; hemodynamics; implant design; improved; individual variation; information processing; normal hearing; predicting response; psychologic; relating to nervous system; response; social; sound; speech in noise

PROJECT SUMMARY / ABSTRACT The most pressing issue with hearing aids and cochlear implants is that they function poorly in noisy environments for most users, where even mild hearing loss can make it difficult to ignore background sound. Suppression of unwanted sound is crucial for communication in social settings, such as the workplace. Inability to understand speech in these situations, called masking, can lead to social isolation and reduced employment. Two principal types of masking interfere with optimal function of hearing aids and cochlear implants. The first type, called energetic masking, is well characterized through psychophysics, physiology and modeling. The second type, called informational masking, is currently only defined as a psychological construct and much less understood. Energetic masking occurs when target speech and background sound excite the same auditory nerve fibers at the same time. Even an ideal listener would be mostly unable to recover an energetically masked target. In contrast, informational masking occurs even when target and background sound do not overlap in time and frequency, and when an ideal listener could restore the target information. Informational masking thus holds a key to improved hearing aid and cochlear implant design. Moreover, individual listeners differ dramatically in their ability to suppress informational masking. However, hearing aids and cochlear implants only intend to mitigate energetic masking, ignoring vulnerability to informational masking. Towards improved fitting of hearing aids and cochlear implants, we propose to develop an objective scale of vulnerability to informational masking based on cortical function. We propose to examine cortical mechanisms of informational masking in humans and in an animal model organism of human auditory processing, the Mongolian gerbil (Meriones unguiculatus). First, we will test normal-hearing human listeners as well as gerbils under conditions of informational masking and simultaneously record from auditory cortex. In humans, we will record the hemodynamic response of blood oxygenation, using a quick and robust assessment technique with clinical relevance. In gerbils, we will measure neuronal activity in auditory cortex from trained animals. We will use this data to develop an objective metric of an individual’s vulnerability to informational masking. Second, we will examine the neuronal mechanisms of informational masking by introducing rapid unpredictable changes in background sound and assessing if high vulnerability to informational masking is due to predominant reliance on suppressing background activity (as opposed to enhanced responses to the target) in humans and gerbils. Third, using our animal model, we will test how hearing loss affects susceptibility to informational masking. Collectively, this proposal will functionally define informational masking at both perceptual and cortical processing levels. The results are expected to significantly advance our understanding of the origins and scope of this central auditory processing deficit in common everyday situations with background sound.

项目概要/摘要 助听器和人工耳蜗最紧迫的问题是它们在嘈杂的环境中功能不佳 对于大多数用户来说，即使是轻微的听力损失也很难忽视背景声音。 抑制不需要的声音对于工作场所等社交环境中的沟通至关重要。 在这些情况下理解言语（称为掩蔽）可能会导致社会孤立和就业减少。 两种主要类型的掩蔽可以最佳地干扰助听器和人工耳蜗的功能。 这种类型被称为能量掩蔽，通过心理物理学、生理学和建模得到了很好的表征。 第二种类型称为信息掩蔽，目前仅被定义为一种心理构造，更不用说 当目标语音和背景声音刺激同一听觉神经时，就会发生能量掩蔽。 即使是理想的聆听者也几乎无法恢复精力充沛的目标。 相反，即使目标声音和背景声音在时间上不重叠，信息掩蔽也会发生。 频率，并且当理想的收听者可以恢复目标信息时，信息掩蔽因此保持。 此外，不同听者的听力差异也很大。 然而，助听器和人工耳蜗的目的只是抑制信息掩蔽。 减轻能量掩蔽，忽略信息掩蔽的脆弱性，以提高拟合度。 助听器和人工耳蜗，我们建议制定一个客观的信息脆弱性量表 基于皮质功能的掩蔽。 我们建议研究人类和动物模型中信息掩蔽的皮质机制 首先，我们将测试人类听觉处理的生物——蒙古沙鼠（Meriones unguiculatus）。 听力正常的人类听众以及信息掩蔽条件下的沙鼠 同时从听觉皮层记录，在人类中，我们将记录血液的血流动力学反应。 我们将使用具有临床相关性的快速而可靠的评估技术来测量沙鼠的氧合情况。 我们将利用这些数据来开发一个客观的衡量标准。 其次，我们将研究个体对信息掩盖的脆弱性。 通过在背景声音中引入快速不可预测的变化并评估是否高来进行信息掩蔽 信息屏蔽的脆弱性是由于主要依赖于抑制后台活动（如 第三，我们将使用我们的动物模型进行测试。 听力损失如何影响信息掩蔽的易感性。 总的来说，该提案将在功能上定义感知和皮质的信息掩蔽 预计结果将大大促进我们对起源和范围的理解。 在有背景声音的常见日常情况下，这种中枢听觉处理缺陷的研究。