MODELS OF SPEECH PERCEPTION BY COCHLEAR IMPLANT USERS

本研究项目的长期目标是了解人工耳蜗（CI）使用者语音的机制，并在此过程中了解心理物理特征的个体差异，这可能解释CI语音感知的个体差异。从这项研究中获得的见解将推进我们对言语感知和适应周边频率图中主要变化的基本知识。项目I的具体目的是预测单个人工耳蜗植入用户的音素识别，基于他们沿沿着指定的感知维度的辨别。为了实现这一目标，我们提出了开发多维音素识别（MPI）模型的语音感知多通道CI用户。这些基于心理物理学的解释性模型：它们不简单地试图基于心理物理测试中的表现来预测言语感知，它们还提供了关于CI用户如何编码和处理输入听觉信号以识别不同言语声音的严格且可验证的假设。MPI模式已经提供了对言语知觉中各种实验发现的可能的心理物理学解释的洞察。项目II解决了CI用户对电刺激引起的感知的适应性表现，由于刺激电极的位置比正常位置更基底，电刺激引起的感知比声刺激引起的感知具有更高的音高。我们建议测量的时间过程中，程度，和可能的限制CI用户所示的适应，在响应于这个更基础的比正常的刺激。这一目标是重要的，不仅因为它将提供临床和科学上有用的见解与CI的语音感知，但也因为CI人口提供了一个独特的机会，调查人类适应修改后的频率图，并因此可以让我们获得新的知识，可塑性的中央听觉系统在成年人。使用项目I中开发的MPI模型，我们将能够获得CI用户对比正常刺激更基础的适应的定量估计。

The long term goal of this research project is to understand the mechanistic that underlie of speech sounds by cochlear implant (CI) users and, in so doing, gain an understanding of the individual differences in psychophysical characteristics which may explain individual differences in speech perception with a CI. Insights gained from this research will advance our basic knowledge about speech perception and adaptation to major change in the peripheral frequency map. The specific aim of Project I is to predict phoneme identification of individual cochlear implant users, based on their discrimination along specified perceptual dimensions. To achieve this aim we proposed to develop Multi-dimensional Phoneme Identification (MPI) models of speech perception by multi-channel CI users. These psychophysically- based models of explanatory: they do not simply attempt to predict speech perception based on performance in psychophysical tests, they also provide strict and verifiable hypotheses about how CI users encode and process the input auditory signal to identify different speech sounds. The MPI mode has already provided insight into possible psychophysical accounts of a variety of experimental findings in speech perception. Project II addresses the adaptation show by CI users to the percepts elicited by electrical stimulation, which are of higher pitch than the percepts elicited by acoustic stimulation, due to the more- basal-than-normal location of the stimulating electrodes. We propose to measure the time course, the extent, and the possible limitations of the adaptation shown by CI users in response to this more-basal-than-normal stimulation. This goal is important not only because it will provide clinically and scientifically useful insights about speech perception with a CI, but also because the CI population presents a unique opportunity to investigate human adaptation to a modified frequency map, and may therefore allow us to obtain new knowledge about plasticity of the central auditory system in adults. Using the MPI models developed in Project I, we will be able to obtain quantitative estimates of a CI users' adaptation to more-basal-than-normal stimulation.