Better place-coding of the fundamental frequency in cochlear implants
Better place-coding of the fundamental frequency in cochlear implants
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DOI：
10.1121/1.1642623
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发表时间：
2004-02-01
影响因子：
2.4
通讯作者：
Wouters, J
中科院分区：
文献类型：
--
作者：
Geurts, L;Wouters, J
在当前的耳蜗植入系统中，复杂声音的基频F0由电极上呈现的电信号的包络中的时间波动编码。与人工耳蜗系统相比，在正常听力中，复杂声音的较低谐波被解析。在本研究中，它是调查是否“位置编码”的第一谐波提高的能力，以区分复杂的声音与不同的基本频率。因此，构造了一种新的滤波器组，对于该滤波器组，一次谐波总是在两个相邻的滤波器中被解析，并且两个滤波器输出之间的平衡与一次谐波的频率直接相关。新的滤波器组进行了比较，通常用于临床处理器中的滤波器组，在刺激中的时间线索的存在和不存在。LAURA人工耳蜗植入体的四名用户参与了音高辨别任务，以确定F0差异的检测阈值。结果表明，这些阈值显着降低新的滤波器组，如果没有时间线索存在于刺激。如果包括时间线索，则两个滤波器组的结果之间的差异变得更小，但是对于新的滤波器组仍然观察到明显的优势。这证明了对基频使用位置编码的可行性。（C）. 2004年，美国声学学会（Acoustical Society of Arnerica）。
In current cochlear implant systems, the fundamental frequency F0 of a complex sound is encoded by temporal fluctuations in the envelope of the electrical signals presented on the electrodes. In normal hearing, the lower harmonies of a complex sound are resolved, in contrast with a cochlear implant system. In the present study, it is investigated whether "place-coding" of the first harmonic improves the ability of an implantee to discriminate complex sounds with different fundamental frequencies. Therefore, a new filter bank was constructed, for which the first harmonic is always resolved in two adjacent filters, and the balance between both filter outputs is directly related to the frequency of the first harmonic. The new filter bank was compared with a filter bank that is typically used in clinical processors, both with and without the presence of temporal cues in the stimuli. Four users of the LAURA cochlear implant participated in a pitch discrimination task to determine detection thresholds for F0 differences. The results show that these thresholds decrease noticeably for the new filter bank, if no temporal cues are present in the stimuli. If temporal cues are included, the differences between the results for both filter banks become smaller, but a clear advantage is still observed for the new filter bank. This demonstrates the feasibility of using place-coding for the fundamental frequency. (C). 2004 Acoustical Society of Arnerica.