An electric frequency-to-place map for a cochlear implant patient with hearing in the nonimplanted ear
An electric frequency-to-place map for a cochlear implant patient with hearing in the nonimplanted ear
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DOI：
10.1007/s10162-007-0071-1
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发表时间：
2007-06-01
影响因子：
2.4
通讯作者：
Finley, Charles
中科院分区：
文献类型：
--
作者：
Dorman, Michael F.;Spahr, Tony;Finley, Charles
本研究的目的是将传递到单个人工耳蜗电极的高速率电刺激的音高与电极插入深度和插入角度相关联。患者（CHI）能够提供电刺激和声刺激之间的音高匹配，因为他的非植入耳在250 Hz至8 kHz范围内的听阈范围为30至60 dB HL。电极深度和插入角度通过患者颞骨的高分辨率计算机断层扫描（CT）测量。扫描用于创建耳蜗的3D图像体积重建，其允许阶内的电极位置的可视化。极限方法用于建立声学纯音和电刺激（1，652-pps，未调制的脉冲序列）之间的音高匹配。音调匹配数据表明，对于大于450度或大于约20 mm插入深度的插入角度，音调在约420 Hz处饱和。从20到15毫米的插入深度间距估计约半个倍频程低于格林伍德功能。从13到3毫米的插入深度的间距估计是大约一个八度低于格林伍德功能。对于仅3.4个单位进入耳蜗的电极的音高匹配为3，447 Hz。这些数据与其他报告一致，例如，Boex等人（2006年）描述了电刺激耳蜗的频率位置图，其中单个电极上刺激的感知音调显着低于毛细胞水平刺激的Greenwood函数预测的音调。
The aim of this study was to relate the pitch of high-rate electrical stimulation delivered to individual cochlear implant electrodes to electrode insertion depth and insertion angle. The patient (CHI) was able to provide pitch matches between electric and acoustic stimulation because he had auditory thresholds in his nonimplanted ear ranging between 30 and 60 dB HL over the range, 250 Hz to 8 kHz. Electrode depth and insertion angle were measured from high-resolution computed tomography (CT) scans of the patient's temporal bones. The scans were used to create a 3D image volume reconstruction of the cochlea, which allowed visualization of electrode position within the scala. The method of limits was used to establish pitch matches between acoustic pure tones and electric stimulation (a 1,652-pps, unmodulated, pulse train). The pitch matching data demonstrated that, for insertion angles of greater than 450 degrees or greater than approximately 20 mm insertion depth, pitch saturated at approximately 420 Hz. From 20 to 15 mm insertion depth pitch estimates were about one-half octave lower than the Greenwood function. From 13 to 3 mm insertion depth the pitch estimates were approximately one octave lower than the Greenwood function. The pitch match for an electrode only 3.4 unit into the cochlea was 3,447 Hz. These data are consistent with other reports, e.g., Boex et al. (2006), of a frequency to-place map for the electrically stimulated cochlea in which perceived pitches for stimulation on individual electrodes are significantly lower than those predicted by the Greenwood function for stimulation at the level of the hair cell.