Binaural Optimization of Cochlear Implants: Discarding Frequency Content Without Sacrificing Head-Shadow Benefit.
Binaural Optimization of Cochlear Implants: Discarding Frequency Content Without Sacrificing Head-Shadow Benefit.
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人工耳蜗的双耳优化：在不牺牲头影效果的情况下丢弃频率内容。
DOI：
10.1097/aud.0000000000000784
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发表时间：
2020
期刊：
影响因子：
3.7
通讯作者：
Bernstein,JoshuaGW
中科院分区：
文献类型：
--
作者：
Sheffield,SterlingW;Goupell,MatthewJ;Spencer,NathanielJ;Stakhovskaya,OlgaA;Bernstein,JoshuaGW
目的：单侧耳聋人工耳蜗植入（SSD-CI）听者和双侧人工耳蜗植入（BI-CI）听者获得接近正常水平的头影益处，但双耳益处有限。这些有限的双耳益处的一个可能原因是耳蜗刺激的位置往往在两耳之间不匹配。SSD-CI和BI-CI患者可能受益于双耳拟合，重新分配频率以减少耳间位置失配。然而，这种方法可能会通过排除来自一只耳朵的低频或高频信息来减少单耳语音识别和头影益处。本研究探讨了有多少频率信息可以排除CI信号在听力差的耳朵，而不减少头影的好处，以及这些结果是如何影响单耳语音recognization.Design的双耳不对称性：语音识别阈值的句子在语音成形噪声测量6成人SSD-CI听众，12 BI-CI听众，和9个正常听力的听众提出声码器模拟。使用非个性化的耳内或耳后头部相关脉冲响应模拟呈现刺激，其中语音从70度方位角（听力较差侧）呈现，噪声从70度方位角（听力较好侧）呈现，从而在听力较差耳处产生更好的信噪比（SNR）。头影效益计算为在听力较差、SNR较好的耳朵中启用CI所获得的双侧语音识别阈值的改善。系统地将高通或低通滤波应用于呈现给听力较差的耳朵的与头部相关的脉冲响应滤波刺激。对于SSD-CI收听者和SSD声码器模拟，仅应用高通滤波，因为CI频率分配永远不需要向下调整以与耳朵频率匹配。对于BI-CI收听器和BI声码器模拟，应用低通和高通滤波。听力正常的听众进行了测试，两个级别的性能，以检查在单耳语音识别（声码器合成滤波器斜率：5或20 dB/octave）的耳间不对称的效果。结果：平均头影的好处是较小的SSD-CI听众（~ 7 dB）比BI-CI听众（~ 14 dB）。对于SSD-CI收听者，可以排除< 1236 Hz的频率;对于BI-CI收听者，< 886 or>可以从听力较差的耳朵中排除3814 Hz的频率，而不会减少头影益处。双边性能表现出更大的免疫过滤比单声道性能，随着滤波器截止的功能，性能的逐渐变化。在单耳性能中具有较大耳间不对称性的真实的和声码器模拟CI用户具有较少的头影益处。
Objectives:Single-sided deafness cochlear-implant (SSD-CI) listeners and bilateral cochlear-implant (BI-CI) listeners gain near-normal levels of head-shadow benefit but limited binaural benefits. One possible reason for these limited binaural benefits is that cochlear places of stimulation tend to be mismatched between the ears. SSD-CI and BI-CI patients might benefit from a binaural fitting that reallocates frequencies to reduce interaural place mismatch. However, this approach could reduce monaural speech recognition and head-shadow benefit by excluding low-or high-frequency information from one ear. This study examined how much frequency information can be excluded from a CI signal in the poorer-hearing ear without reducing head-shadow benefits and how these outcomes are influenced by interaural asymmetry in monaural speech recognition.Design:Speech-recognition thresholds for sentences in speech-shaped noise were measured for 6 adult SSD-CI listeners, 12 BI-CI listeners, and 9 normal-hearing listeners presented with vocoder simulations. Stimuli were presented using nonindividualized in-the-ear or behind-the-ear head-related impulse-response simulations with speech presented from a 70 azimuth (poorer-hearing side) and noise from 70 (better-hearing side), thereby yielding a better signal-to-noise ratio (SNR) at the poorer-hearing ear. Head-shadow benefit was computed as the improvement in bilateral speech-recognition thresholds gained from enabling the CI in the poorer-hearing, better-SNR ear. High-or low-pass filtering was systematically applied to the head-related impulse-response–filtered stimuli presented to the poorer-hearing ear. For the SSD-CI listeners and SSD-vocoder simulations, only high-pass filtering was applied, because the CI frequency allocation would never need to be adjusted downward to frequency-match the ears. For the BI-CI listeners and BI-vocoder simulations, both low and high pass filtering were applied. The normal-hearing listeners were tested with two levels of performance to examine the effect of interaural asymmetry in monaural speech recognition (vocoder synthesis-filter slopes: 5 or 20 dB/octave).Results:Mean head-shadow benefit was smaller for the SSD-CI listeners (~ 7 dB) than for the BI-CI listeners (~ 14 dB). For SSD-CI listeners, frequencies< 1236 Hz could be excluded; for BI-CI listeners, frequencies< 886 or> 3814 Hz could be excluded from the poorer-hearing ear without reducing head-shadow benefit. Bilateral performance showed greater immunity to filtering than monaural performance, with gradual changes in performance as a function of filter cutoff. Real and vocoder-simulated CI users with larger interaural asymmetry in monaural performance had less head-shadow benefit.Conclusions: