A Binaural Cochlear Implant Sound Coding Strategy Inspired by the Contralateral Medial Olivocochlear Reflex
A Binaural Cochlear Implant Sound Coding Strategy Inspired by the Contralateral Medial Olivocochlear Reflex
复制标题
受对侧内侧橄榄耳蜗反射启发的双耳耳蜗植入声音编码策略
作者：
E. Lopez;Almudena Eustaquio;Joshua S. Stohl;R. Wolford;R. Schatzer;B. Wilson
目的：在自然听力中，耳蜗机能通过传出的内侧橄榄内侧反射(MOCR)进行动态调节。这些调整可能有助于理解在嘈杂环境中的语音，而目前的人工耳蜗术(CI)的使用者无法使用这些调整。本研究的目的是：(1)提出一种双耳CI声音处理策略，其灵感来自于自然听力中对侧MOCR提供的耳蜗声压缩控制；以及(2)评估新策略对于理解在语音和噪声源的不同空间构型中与稳态噪声竞争的语音的益处。设计：构建成对的CI声音处理器(每个耳朵一个)，以模仿或不模仿对侧MOCR对压缩的影响。对于非模仿条件(标准策略或STD)，一对中的两个处理器的功能类似于标准临床处理器(即，具有固定的后端压缩，并且彼此独立)。当被配置为模拟MOCR(MOC策略)的效果时，两个处理器彼此通信，并且该对中的每个处理器的给定频道中的后端压缩量随着对侧处理器中相应频道的输出能量的增加/减少而动态地减少/增加(使得输出电平下降/增加)。对3例双侧CI患者和2例单侧聋单侧CI患者进行了言语形状噪声条件下的言语接收阈值测试。比较了单侧和双侧听力条件下STD和MOC策略的阈值，以及模拟自由场条件下语音和噪声源的三种空间配置：语音和噪声源并置在听者前面，左耳语音和噪声在听者前面，语音在左耳和噪声在右耳。在双侧和单侧听力中，传递到测试耳(S)的电刺激总是被计算为好像听者戴着双边处理器一样。结果：在单侧和双侧听力条件下，语音接收阈值与语音和噪声源并置的两种策略相当，但对于空间分离的语音和噪声源，MOC至少比STD策略低2分贝(更好)。在单边听力条件下，无论采用何种策略，随着语音和噪声源空间间隔的增加，平均阈值都会得到改善，但在MOC策略下，改善的幅度更大。在双边听力条件下，只有在MOC策略下，随着语音-噪声空间分离的增加，阈值显著提高。结论：MOC策略(1)显著提高了在单侧和双侧听条件下与空间分离噪声源竞争时呈现的语音的清晰度；(2)在双侧听条件下产生了显著的空间释放，这是固定压缩条件下所没有的；(3)增强了在单侧听条件下从掩蔽中释放的空间。这里实施的MOC策略或其修改版本可以有效地应用于CI和助听器。
Objectives: In natural hearing, cochlear mechanical compression is dynamically adjusted via the efferent medial olivocochlear reflex (MOCR). These adjustments probably help understanding speech in noisy environments and are not available to the users of current cochlear implants (CIs). The aims of the present study are to: (1) present a binaural CI sound processing strategy inspired by the control of cochlear compression provided by the contralateral MOCR in natural hearing; and (2) assess the benefits of the new strategy for understanding speech presented in competition with steady noise with a speech-like spectrum in various spatial configurations of the speech and noise sources. Design: Pairs of CI sound processors (one per ear) were constructed to mimic or not mimic the effects of the contralateral MOCR on compression. For the nonmimicking condition (standard strategy or STD), the two processors in a pair functioned similarly to standard clinical processors (i.e., with fixed back-end compression and independently of each other). When configured to mimic the effects of the MOCR (MOC strategy), the two processors communicated with each other and the amount of back-end compression in a given frequency channel of each processor in the pair decreased/increased dynamically (so that output levels dropped/increased) with increases/decreases in the output energy from the corresponding frequency channel in the contralateral processor. Speech reception thresholds in speech-shaped noise were measured for 3 bilateral CI users and 2 single-sided deaf unilateral CI users. Thresholds were compared for the STD and MOC strategies in unilateral and bilateral listening conditions and for three spatial configurations of the speech and noise sources in simulated free-field conditions: speech and noise sources colocated in front of the listener, speech on the left ear with noise in front of the listener, and speech on the left ear with noise on the right ear. In both bilateral and unilateral listening, the electrical stimulus delivered to the test ear(s) was always calculated as if the listeners were wearing bilateral processors. Results: In both unilateral and bilateral listening conditions, mean speech reception thresholds were comparable with the two strategies for colocated speech and noise sources, but were at least 2 dB lower (better) with the MOC than with the STD strategy for spatially separated speech and noise sources. In unilateral listening conditions, mean thresholds improved with increasing the spatial separation between the speech and noise sources regardless of the strategy but the improvement was significantly greater with the MOC strategy. In bilateral listening conditions, thresholds improved significantly with increasing the speech-noise spatial separation only with the MOC strategy. Conclusions: The MOC strategy (1) significantly improved the intelligibility of speech presented in competition with a spatially separated noise source, both in unilateral and bilateral listening conditions; (2) produced significant spatial release from masking in bilateral listening conditions, something that did not occur with fixed compression; and (3) enhanced spatial release from masking in unilateral listening conditions. The MOC strategy as implemented here, or a modified version of it, may be usefully applied in CIs and in hearing aids.
双侧人工耳蜗的中央掩蔽。
DOI：
10.1121/1.4773262
发表时间：
2013
期刊：
The Journal of the Acoustical Society of America
影响因子：
--
作者：
Lin,Payton;Lu,Thomas;Zeng,Fan-Gang
通讯作者：
Zeng,Fan-Gang
动态范围压缩对正常听力听众的空间选择性听觉注意力的影响。
DOI：
10.1121/1.4794386
发表时间：
2013
期刊：
The Journal of the Acoustical Society of America
影响因子：
--
作者：
Schwartz,AndrewH;Shinn-Cunningham,BarbaraG
通讯作者：
Shinn-Cunningham,BarbaraG