Susceptibility to and Release from Masking in Infancy and Childhood

描述（由申请人提供）：婴儿和儿童比成人更容易受到竞争背景声音的干扰。对于听力正常的儿童，这些听觉掩蔽的发育影响可能是实质性的，但对于听力受损的儿童则更为明显。尽管婴儿必须在相互竞争的声音中学习言语和语言，但我们对影响儿童在噪音中听力的因素的了解有限，而且很少有研究解决婴儿和听力障碍儿童面临的具体挑战。该项目的长期目标是确定和解释在包含多个声源的复杂声学环境中导致听力发展的因素。拟议的实验将描述在竞争性背景声中听到目标音调或言语的能力的发育影响，并将确定声音线索组合，以改善正常听力和听力受损的婴儿和儿童在噪音中的听力。目的1将描述从婴儿期到青春期远程频率掩蔽的发展时间过程。拟议的研究将验证对远距离背景声音干扰的易感性随着年龄的增长而降低的假设。目的2将调查婴儿和儿童在存在竞争背景声音的情况下，从提供稳健和/或冗余的听觉分组线索中受益的程度。这些研究将验证一个假设，即当声源隔离线索相对较少时，婴儿和儿童从声源隔离线索中受益的程度低于成年人。目标3将识别在存在竞争性背景声音的情况下改善听力的声音线索，用于听力障碍的婴儿和儿童。本研究将验证一个假设，即听力障碍会干扰与从背景声音中分离和选择目标声音相关的听觉处理能力。为这三个目标提出的实验都依赖于严格的行为方法，使用特征良好的多音调和噪声刺激，以及在竞争噪声或语音掩蔽物存在下的语音感知测试。本研究的结果将提供急需的规范性数据，并有望有助于形成儿童复杂听觉感知的测量方法。这些数据也有可能导致改进策略，以优化听力障碍婴儿和儿童的听觉信息传递。

DESCRIPTION (provided by applicant): Infants and children are more vulnerable to interference from competing backgrounds sounds than adults. These development effects in auditory masking can be substantial for children with normal hearing sensitivity, but are more pronounced for children with hearing impairment. Despite the fact that infants must learn about speech and language in the presence of competing sounds, we have a limited understanding of the factors that influence children's hearing in noise, and few studies have addressed the specific challenges faced by infants and children with hearing impairment. The long-term aim of this project is to identify and explain the factors responsible for the development of hearing in complex acoustic environments that contain multiple sources of sound. The proposed experiments will characterize developmental effects in the ability to hear target tones or speech in the presence of competing background sounds and will identify acoustic-cue combinations that improve hearing in noise for both normal-hearing and hearing-impaired infants and children. Aim 1 will delineate the time course of development for remote-frequency masking from infancy to adolescence. The proposed studies will test the hypothesis that susceptibility to interference from remote-frequency background sounds decreases with increasing age. Aim 2 will investigate the extent to which infants and children benefit from the provision of robust and/or redundant auditory grouping cues in the presence of competing background sounds. These studies will test the hypothesis that infants and children benefit less than adults from sound source segregation cues when those cues are relatively sparse. Aim 3 will identify acoustic cues that improve hearing in the presence of competing background sounds for infants and children with hearing impairment. This work will test the hypothesis that hearing impairment interferes with auditory processing abilities related to the segregation and selection of target from background sounds. Experiments proposed for all three aims rely on rigorous behavioral methods using well-characterized multi-tonal and noise stimuli as well as speech perception testing in the presence of competing noise or speech maskers. The results of the proposed studies will provide much needed normative data and are expected to contribute to the formation of pediatric measures of complex auditory perception. There is also the potential these data will lead to improved strategies to optimize the delivery of auditory information for infants and children with hearing impairment.