Models of Speech Perception by Cochlear Implant Users

描述（由申请人提供）：本研究项目的长期目标是了解人工耳蜗使用者语音感知的机制，成人听觉感知学习的特征，以及两者之间的潜在联系。提出的研究的第一个具体目标是为个人Cl用户开发音素和单词识别的数学模型。我们将改进和扩展CI用户的语音感知模型，该模型基于用户对特定感知维度的歧视。这些基于心理物理学的模型是解释性的：它们不仅试图预测语音感知测试的总分，而且还提供了关于CI用户处理听觉信号以识别不同语音的机制的具体假设。本提案的第二个具体目的是研究后语言聋人的听觉适应，他们接收的语音信号既频谱退化又频率移位。我们将度量CI用户显示的适应的范围、时间进程和可能的限制。除了其强烈的临床兴趣外，这一特定目标在科学上也很重要，因为CI人群提供了一个独特的机会来研究对修改频率图的适应性，并可能使我们获得有关成人中枢听觉系统可塑性的新知识。项目1中开发的数学模型将提供一种方法来估计CI用户对不匹配频率映射的适应情况。第三个具体目标是测试一种渐进式训练方法，这种方法可以促进语后聋Cl使用者的听觉适应。将采用前瞻性随机双盲试验比较渐进式和标准的Crs频率制图方法。我们将检查CI用户和听力正常的听众；后者将在听到CI的声学模型时进行研究，并将参与成像会议，以寻找听觉学习过程的功能性神经生物学相关性。如果成功，这项研究将成为转化研究的一个例子，在转化研究中，使用CI用户的感知学习和适应的基本知识来设计改进的临床程序。拟议的研究计划涵盖从基础到临床再到应用的范围。从这个项目中获得的见解将提高我们对语音感知和适应周围频率图变化的基本知识，也可能导致潜在的重要临床应用。

DESCRIPTION (provided by applicant): The long-term goals of this research project are to understand the mechanisms that underlie speech perception by cochlear implant (CI) users, the characteristics of auditory perceptual learning in adults, and the potential links between the two. The first specific aim of the proposed research is to develop mathematical models of phoneme and word identification for individual Cl users. We will refine and extend our models of speech perception by CI users, which are based on the users' discrimination along specified perceptual dimensions. These psychophysically-based models are explanatory:, they do not simply attempt to predict overall scores in speech perception tests, they also provide specific hypotheses about the mechanisms CI users employ to process the auditory signal to identify different speech sounds. The second specific aim of this proposal is to investigate auditory adaptation in postlingually deaf Cl users, who receive speech signals that are both spectrally degraded and shifted in frequency. We will measure the extent, time course, and possible limitations of the adaptation shown by CI users. In addition to its strong clinical interest, this specific aim is scientifically important because the CI population presents a unique opportunity to investigate adaptation to a modified frequency map, and may allow us to obtain new knowledge about central auditory system plasticity in adults. The mathematical models developed in Project I will provide one of the methods to estimate a CI user's adaptation to a mismatched frequency map. The third specific aim is to test a gradual training approach that may facilitate auditory adaptation in postlingually deaf Cl users. The gradual and standard approaches to frequency mapping in Crs will be compared using a prospective randomized double-blind trial. We will examine both CI users and normal hearing listeners; the latter will be studied while hearing an acoustic model of a CI and will participate in imaging sessions that will search for functional neurobiological correlates of the auditory learning process. If successful, this study would be an example of translational research where basic knowledge about perceptual learning and adaptation in CI users is used to design improved clinical procedures. The proposed research program spans the range from basic to clinical to applied. Insights gained from this program will advance our basic knowledge about speech perception and adaptation to changes in the peripheral frequency map, and may also result in potentially important clinical applications.