Development of Frequency Resolution in Infancy

婴儿期频率分辨率的发展

• 批准号: 8386873
• 负责人: Lynne A. Werner
• 金额: $ 35.66万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-06-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8386873
• 关键词: Acoustics; Address; Adult; Affect; Age; Age-Months; Attention; Auditory; Auditory Evoked Potentials; Auditory area; Auditory system; Brain Stem; Child; Complex; Development; Dimensions; Discrimination; Elderly; Environment; Failure; Frequencies; Goals; Hearing; Human; Infant; Intervention; Laboratories; Language; Language Disorders; Learning; Masks; Modeling; Nature; Nervous system structure; Neural Pathways; Outcome; Output; Pathway interactions; Perception; Performance; Process; Property; Psychoacoustics; Psychophysiology; Research; Resolution; Shapes; Side; Signal Transduction; Source; Speech; Stream; Television; Testing; Time; Work; age related; auditory pathway; base; effective intervention; experience; infancy; neurodevelopment; neuromechanism; perceptual organization; programs; relating to nervous system; research study; selective attention; sound

DESCRIPTION (provided by applicant): The long-term goal of this program of research is to describe and to understand changes in hearing that occur during human infancy. Recent work has focused on infants' ability to process one sound in the presence of competing sounds. The results show that the sound properties that influence this ability differ between adults and 7-9-month-old infants, suggesting that the mechanisms underlying listening in complex environments are also different. A new synthesis of work describing the development of auditory neural pathways leads to new hypotheses concerning the nature of such age-related changes in hearing. Specifically, it appears that the source of input to auditory cortex shifts around 6 months of age. If that is the case, then infants younger than 6 months are predicted to respond in a qualitatively different way from infants older than 6 months to situations in which selective processing of one sound in the presence of another is required. The goal of the proposed work is to test that general hypothesis. The proposed experiments address three specific aims. The first aim is to determine whether 3- and 7-month-old infants are able to extract some of the important sound attributes- pitch, spectral shape, and modulation-that are used by adults to separate competing sounds into different auditory streams. Infants' ability to discriminate vowels and musical notes that differ along these dimensions will be tested. It is hypothesized that infants will be able to discriminate sounds along all three dimensions. The second specific aim is to determine whether 3- and 7-month-old infants are able to separate two concurrent streams of vowels or musical notes. The concurrent streams will differ along the dimensions of pitch, spectral shape and modulation, according to the results of the experiments addressing the first specific aim. Infants' ability to discriminate a change in a vowel or musical note in one stream in the presence of an unchanging stream will be tested. It is hypothesized that both 3-month-olds and 7-month-olds will be able to perform this task when the streams differ in spectral shape and perhaps modulation, but not when they differ in pitch. The third specific aim is to determine whether 3- and 7-month-old infants are able to selectively process a change in a vowel or musical note in only one of two streams when the same change can occur in the competing stream. Infants' ability to discriminate a change in a vowel or musical note in a specific stream will be tested, but under conditions in which the same change sometimes occurs in the competing stream. It is hypothesized that 7-month-olds, but not 3-month-olds will be able to perform this task. The results of these experiments will have implications for current models of auditory neural development and for models of perceptual organization in mature listeners. PUBLIC HEALTH RELEVANCE: Infants in the developed world often learn speech and language in a background of competing sounds from television and other sources. The work proposed in this application will determine what infants of different ages can hear under such conditions. The results may be important in understanding why some children develop language disorders and in refining interventions for hearing-impaired infants.

描述(由申请者提供)：本研究项目的长期目标是描述和理解人类婴儿期听力的变化。最近的研究集中在婴儿在存在竞争声音的情况下处理一种声音的能力。结果表明，影响这一能力的声音特性在成人和7-9个月大的婴儿中是不同的，这表明在复杂环境中潜在的倾听机制也不同。描述听觉神经通路发展的一项新的工作综述导致了关于这种与年龄相关的听力变化的性质的新假设。具体地说，似乎听觉皮质的输入来源在6个月左右发生了变化。如果是这样的话，预计6个月以下的婴儿对需要选择性处理一个声音和另一个声音的情况的反应方式与6个月以上的婴儿有质的不同。这项拟议工作的目标是检验这一普遍假设。拟议的实验涉及三个具体目标。第一个目标是确定3个月和7个月大的婴儿是否能够提取一些重要的声音属性--音高、频谱形状和调制--成年人用这些属性将相互竞争的声音区分成不同的听觉流。婴儿辨别在这些维度上不同的元音和音符的能力将被测试。据推测，婴儿将能够在所有三个维度上辨别声音。第二个具体目标是确定3个月和7个月大的婴儿是否能够分离两个同时出现的元音或音符。根据针对第一个特定目标的实验的结果，并发的流在音调、光谱形状和调制的维度上将不同。婴儿在一个音流中辨别元音或音符变化的能力 将测试是否存在不变的流。据推测，3个月大的婴儿和7个月大的婴儿都能够在频谱形状和调制方式不同的情况下执行这项任务，但当它们的音调不同时就不能执行这项任务。第三个具体目标是确定3个月和7个月大的婴儿是否能够有选择地处理两个流中只有一个的元音或音符的变化，而相同的变化可能发生在竞争的流中。婴儿辨别特定音流中元音或音符变化的能力将被测试，但条件是竞争的音流中有时会发生同样的变化。据推测，7个月大的婴儿能够完成这项任务，但3个月大的婴儿不能。这些实验的结果将对现有的听觉神经发育模型和成熟听者的知觉组织模型产生影响。 与公共卫生相关：发达国家的婴儿经常在电视和其他来源的竞争声音的背景下学习言语和语言。这项申请中提出的工作将确定不同年龄的婴儿在这种情况下能听到什么。这一结果可能对理解一些儿童发展语言障碍的原因以及完善对听力受损婴儿的干预措施具有重要意义。