A Study on an Cochlear Implant System with a Reverse Solution of a Model for the Peripheral Auditory System

声音（也包括和考虑环境声音）被有效地改变为耳蜗植入物的20个通道的电极脉冲。为此，对语音编码系统常用的多脉冲语音编码算法进行扩展，在时频空间上求最优解，以确定耳蜗基底膜沿着的最佳脉冲位置（在时间轴上）和电极位置（在频率轴上）。通过对优化准则问题的重新审视，采用波形和频谱的最小平方误差准则方法取得了较好的效果，建立了基于电极脉冲刺激下神经放电模式生理学实验模型的声学仿真系统。该方法可以根据电极刺激信号进行精确的声学模拟，并按照外周听觉系统生理学模型的逆过程进行模拟， ...更多信息 从听觉神经的放电模式再现输入的听觉信号。考虑到从神经递质的量恢复基底膜振动的非线性逆模型的各种限制条件，创建了“逆听觉模型”，使得可以再现没有失真的输入声音。耳蜗受试者听到什么“声音”？果然，“声音模拟”认为，我们想获得一定的关键问题，它是否对应于“声音”，这是听到一个人工耳蜗植入者，并详细采访了几十人谁在滨松医学院植入。于是，接下来的事情就明白了。在声学模拟中的模仿接近于连接到耳蜗植入物的时刻的“声音”。然后，一个耳蜗初学者很快就学会了（不到几分钟）。几个月后，他们相信它会像以前一样听得见。也许人们与记忆中的“声音”联系在一起，听过一次，在声学模拟中，虽然由于信号合成的技术问题，声音的失真和噪声的混合经常发生，但很明显，这对于耳蜗植入者来说完全是无关紧要的问题。因此，可以说，耳蜗植入声音的音质评估一定不会由于在声学模拟时产生不必要的失真而被错误。少

A sound (environmental sound is also included and considered) is efficiently changed into the electrode pulses of 20 channels of a cochlear implant. For this purpose, expanding an algorithm of the multi-pulse voice coding usually used by the voice coding system, it was going to calculate the optimum solution in a time-frequency space to determine the optimum pulse position (on a time-axis) and the electrode position (on a frequency-axis) along the basilar-membrane in a cochlea. As a result of looking over the problem of an optimization criterion again, good results were obtained by the method of the minimum-squared-error criterion of waveform and spectrum.The acoustic simulation system based on the physiology experiment model of the auditory-nerve firing pattern by electrode pulse stimulus was created. This can perform an accurate acoustic simulation now from an electrode stimulus signal.The reverse process of the physiology model of a peripheral auditory system was followed, and the a … More coustic signal of an input was reproduced from the firing pattern of an auditory nerve. The "reverse hearing model" was created so that input sound with no distortion might be reproduced, in consideration of various restriction conditions of the nonlinear reverse model that restores basilar-membrane vibration from quantity of a nerve transmitter.What "sound" do cochlear implantees hear? Sure enough, the "sound simulation" considered that we wanted to obtain a certain key to the question whether it corresponds to the "sound" which is hearing a cochlear implantee, and interviewed in detail dozens of people who have implanted at the Hamamatsu medical college. As a result, the following thing was understood. Imitating in an acoustic simulation is close to "sound" of the moment of the hookup to a cochlear implant. Then, a cochlear implantee has learned quickly (less than to several minutes). It becomes audible as before after several months as far as they believe. Perhaps people relates with the "sound" in ones memory that was being listened to once.In the acoustic simulation, although the distortion of sound and mixing of noise often happened for the sake of the technical problem on signal composition, it became clear that it is entirely an unrelated problem for a cochlear implantee. Therefore, it can be said that tone-quality evaluation of cochlear-implant sound must not be mistaken by having produced an unnecessary distortion at the time of an acoustic simulation. Less