AUDITORY SENSITIVITY AND FREQUENCY RESOLUTION IN INFANTS

婴儿的听觉灵敏度和频率分辨率

• 批准号: 6104367
• 负责人: R FOLSOM
• 金额: --
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6104367
• 关键词: Downs syndrome; age difference; auditory pathways; auditory stimulus; auditory threshold; child physical development; cochlea; developmental neurobiology; electroencephalography; hearing tests; human subject; infant human (0-1 year); neural information processing; otoacoustic emission; psychoacoustics; sound; sound frequency; sound impedance

The long term objective of this project is to increase knowledge of the age-dependent changes in auditory responsiveness that occur early in life. The first goal of this study is to investigate the development of frequency resolution in the human auditory system. The primary means of assessing frequency resolution will be through the use of pure-tone masked tuning curves constructed using transient-evoked otoacoustic emissions (TEOAE) and waves I and V of the auditory brainstem response (ABR). Experiments will test the hypothesis that frequency resolution is more "adult-like" at the peripheral level (TEOAE and ABR wave I) compared to a central level (ABR wave V). The second goal is to identify those mechanisms which underlie age- related change in physiologic responses to auditory stimuli early in life. Simultaneous development of the external- and middle-ear, sensory apparatus, and neural pathway likely contribute to the changes observed in infant responses to sound. Addressing the influence of these structures in normal-developing infants is confounded by the fact that the development of different structures likely occurs simultaneously and may be highly correlated. One way to address specific elements of this developmental course is to examine an auditory system that has known disorders. To this end we will test the hypothesis that inherent auditory system abnormalities in infants with Down syndrome will influence physiologic measures from the middle ear, cochlea, and neural pathway. Assessing the performance of physiologic and acoustic tools in these infants will extend our knowledge of these tools, as well as the underlying auditory system itself. The characteristics of physiologic responses -- ABR, otoacoustic emissions, and acoustic measures of middle- ear input impedance -- will be determined in infants with Down syndrome. Two sets of experiments are proposed. The first addresses 1) whether properties of the infant external and middle ear influence ABR threshold, and 2) whether change in frequency resolution across age is determined by peripheral mechanisms or central maturation in the auditory pathway. The experiments in the second set are designed to characterize inherent anatomical abnormalities in infants with Down syndrome using physiologic measures of cochlear function and middle-ear impedance.

该项目的长期目标是增加对 听觉反应能力的年龄依赖性变化发生在早期 生活。 本研究的首要目标是调查 人类听觉系统的频率分辨率。 主要手段为 评估频率分辨率将通过使用纯音 使用瞬态诱发耳声学构建的掩蔽调谐曲线 听觉脑干反应的发射 (TEOAE) 和波 I 和 V （ABR）。 实验将检验频率分辨率的假设 在外周水平上更“像成人”（TEOAE 和 ABR 波 I） 与中心水平（ABR 波 V）相比。 第二个目标是确定年龄相关的机制。 早期对听觉刺激的生理反应的相关变化 生活。 外耳和中耳同时发育，感觉 装置和神经通路可能有助于观察到的变化 婴儿对声音的反应。 解决这些问题的影响 正常发育的婴儿的结构因以下事实而令人困惑： 不同结构的发展可能同时发生并且 可能是高度相关的。 解决此问题特定要素的一种方法 发展过程是检查已经知道的听觉系统 失调。 为此，我们将检验以下假设： 唐氏综合症婴儿的听觉系统异常 影响中耳、耳蜗和神经的生理测量 途径。 评估生理和声学工具的性能 这些婴儿将扩展我们对这些工具的知识，以及 潜在的听觉系统本身。 生理特点 反应——ABR、耳声发射和中耳声学测量 耳朵输入阻抗——将在患有唐氏综合症的婴儿中确定。 提出了两组实验。 第一个地址 1) 是否 婴儿外耳和中耳的特性影响 ABR 阈值， 2）是否确定频率分辨率随年龄的变化 通过听觉通路中的外周机制或中枢成熟。 第二组实验旨在表征固有的 使用生理学研究唐氏综合症婴儿的解剖异常 耳蜗功能和中耳阻抗的测量。