Mismatch negativity (MMN) objectively reflects timbre discrimination thresholds in normal-hearing listeners and cochlear implant users
Mismatch negativity (MMN) objectively reflects timbre discrimination thresholds in normal-hearing listeners and cochlear implant users
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DOI：
10.1016/j.brainres.2014.08.045
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发表时间：
2014-10-24
期刊：
影响因子：
2.9
通讯作者：
Wagner, Luise
中科院分区：
文献类型：
--
作者：
Rahne, Torsten;Plontke, Stefan K.;Wagner, Luise
人工耳蜗 (CI) 用户的音色感知能力较差。大多数行为研究都是用在不止一种音色维度上不同的真实乐器声音来评估音色辨别力。本研究的重点是单一音色维度的个体歧视的客观测量。对 15 名 CI 用户和 15 名正常听力 (NH) 听众进行了音色歧视的心理声学和电生理学病例对照研究。在自适应三选择强制选择程序中测量了复杂音调的时间包络（TE）调制差异和频谱分布（S）差异的显着差异（JND）。根据各个 JND，计算各个四个音调对：时间包络调制/频谱分布音色辨别以及高于/低于 JND。通过这些音调对，提出了四种随机排列的奇怪范式来导出失配负性（MMN），这反映了自动检测声学变化的能力。可以为所有 NH 监听器导出 JND。对于 CI 用户来说，区分频谱分布差异，特别是时间包络调制差异更加困难。当音色差异高于个体 JND 时，MMN 出现在所有 NH 听众和 CI 用户中，但低于 JND 时则不存在。因此，“异常”和“标准”音调之间的音色差异反映了自动检测音色变化的个体阈值。我们的结论是，NH 听众和 CI 用户的音色感知技能可以通过心理声学测量和 MMN 录音来评估音色维度。 MMN 的发生反映了个体 JND 的时间包络调制和频谱分布差异，可用作监测 CI 手术后听觉语言治疗的临床工具。 (C) 2014 Elsevier B.V. 保留所有权利。
Timbre perception is poor in cochlear implant (CI) users. Most behavioral studies assess timbre discrimination with real instrumental sounds differing in more than one timbre dimension. This study focuses on objective measures of individual discrimination of single timbre dimensions. A psychoacoustic and electrophysiological case-control study of timbre discrimination was conducted in 15 CI users and 15 normal-hearing (NH) listeners. Just noticeable differences (JNDs) for temporal envelope (TE) modulation differences and spectral distribution (S) differences of complex tones were measured in an adaptive three-alternatives forced-choice procedure. From individual JNDs, individual four tone pairs were computed: temporal envelope modulation/spectral distribution timbre discrimination, and above/below JND. With these tone pairs, four randomly arranged oddball paradigms were presented to derive mismatch negativity (MMN), which reflects the ability to automatically detect acoustic changes. JNDs could be derived for all NH listeners. Discrimination of spectral distribution differences and particularly temporal envelope modulation differences were more difficult for CI users. MMN was present in all NH listeners and CI users when the timbre difference was above the individual JND, but not when below JND. Thus, the timbre difference between 'deviant' and 'standard' tones reflected the individual threshold for automatic detection of timbre changes. We conclude that the timbre perception skills of NH listeners and CI users in particular can be assessed timbre dimension specifically with psychoacoustic measurements and MMN recordings. MMN occurrence reflects the individual JND for temporal envelope modulation and spectral distribution differences and can be used as a clinical tool to monitor auditory-verbal therapy after CI surgery. (C) 2014 Elsevier B.V. All rights reserved.