We simulated the effect of several automatic gain control (AGC) and AGC-like systems and head movement on the output levels, and resulting interaural level differences (ILDs) produced by bilateral cochlear-implant (CI) processors. The simulated AGC systems included unlinked AGCs with a range of parameter settings, linked AGCs, and two proprietary multi-channel systems used in contemporary CIs. The results show that over the range of values used clinically, the parameters that most strongly affect dynamic ILDs are the release time and compression ratio. Linking AGCs preserves ILDs at the expense of monaural level changes and, possibly, comfortable listening level. Multichannel AGCs can whiten output spectra, and/or distort the dynamic changes in ILD that occur during and after head movement. We propose that an unlinked compressor with a ratio of approximately 3:1 and a release time of 300–500 ms can preserve the shape of dynamic ILDs, without causing large spectral distortions or sacrificing listening comfort.

中文翻译：

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进一步模拟人工耳蜗预处理和头部运动对耳间水平差异的影响

我们模拟了几种自动增益控制 (AGC) 和类似 AGC 的系统以及头部运动对输出电平的影响，以及由双侧人工耳蜗 (CI) 处理器产生的耳间电平差 (ILD)。模拟的 AGC 系统包括具有一系列参数设置的未链接 AGC、链接 AGC 以及当代 CI 中使用的两个专有多通道系统。结果表明，在临床使用的数值范围内，对动态 ILD 影响最大的参数是释放时间和压缩比。连接 AGC 可以保留 ILD，但会牺牲单声道电平的变化，并且可能会降低舒适的聆听电平。多通道 AGC 可以使输出光谱变白，和/或扭曲在头部运动期间和之后发生的 ILD 的动态变化。