MODELS OF SPEECH PERCEPTION BY COCHLEAR IMPLANT USERS

这项研究的长期目标是了解人工耳蜗者语音的机制，从而了解个体在心理物理特征上的差异，这可能解释人工耳蜗者在言语知觉上的个体差异。从这项研究中获得的见解将增进我们对语音感知和对外围频率图重大变化的适应的基本知识。项目I的具体目标是预测个人人工耳蜗者的音素识别，基于他们在特定知觉维度上的辨别能力。为了实现这一目标，我们提出了建立多通道CI用户语音感知的多维音素识别(MPI)模型。这些基于心理物理的解释模型：它们不仅试图根据心理物理测试中的表现来预测言语感知，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语音的严格和可验证的假设。MPI模式已经为言语感知的各种实验结果提供了可能的心理物理解释。项目II涉及CI用户对电刺激引起的知觉的适应，由于刺激电极的位置比正常位置更基本，电刺激引起的知觉比声刺激引起的知觉具有更高的音调。我们建议测量CI使用者对这种比正常刺激更基本的刺激所表现出的适应的时间进程、程度和可能的局限性。这个目标很重要，不仅因为它将提供关于CI的言语感知的临床和科学上有用的见解，而且因为CI人群提供了一个独特的机会来研究人类对修改后的频率图的适应，因此可能允许我们获得关于成人中枢听觉系统可塑性的新知识。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本的刺激的适应程度的定量估计。

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.