Contralateral Interference Caused by Binaurally Presented Competing Speech in Adult Bilateral Cochlear-Implant Users.
Contralateral Interference Caused by Binaurally Presented Competing Speech in Adult Bilateral Cochlear-Implant Users.
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DOI：
10.1097/aud.0000000000000470
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发表时间：
2018
期刊：
影响因子：
3.7
通讯作者：
Bernstein JGW
中科院分区：
文献类型：
--
作者：
Goupell MJ;Stakhovskaya OA;Bernstein JGW
双侧人工耳蜗植入体（BI-CI）旨在改善存在干扰声音时的声音定位和言语理解。对于听力正常的听众，在干扰声存在的情况下，可以通过单耳头影和双耳去掩蔽来提高语音理解。虽然一些BI-CI听众在某些测试条件下经历双耳暴露，但其他人似乎没有。这项研究测试了一组BI-CI用户，他们的听力历史与双耳处理不良有关-早期耳聋或仅一只耳朵长期耳聋。我们预测，这些听众将经历与双耳暴露相反的情况（即，对侧干扰），当试图理解存在竞争说话者的讲话时。9名在生命早期听力受损或有不对称听力史的成人BI-CI用户（例如，一只耳朵耳聋的持续时间更长）参与了这项研究。的坐标响应测量（CRM）语料库被用来评估言语理解的男性目标说话者在安静或在一个男性竞争说话者的存在。实验1测量双耳暴露在一个范例，提供了没有头阴影组件。目标总是以单耳方式呈现，而目标则以单耳或双耳方式呈现。实验2测量空间释放掩蔽的范式，包括一个头阴影组件和可能的双耳unmasking组件。使用非个性化的头部相关传递函数来模拟说话者在前方或向左或向右90°的位置。在实验1中，所有9名听众都经历了对侧干扰（平均9 dB）。四名听众表现出大致对称的对侧干扰，五名听众经历了不对称的对侧干扰。在实验2中，听众经历了平均只有1分贝的空间释放掩蔽，这少量可能是实验1中观察到的对侧干扰的结果。结果最好的解释是安静时言语理解的个体差异，这与同侧耳耳聋的持续时间显著相关。具体而言，不对称对侧干扰的实例可以对应于不对称的听力历史。双侧人工耳蜗植入应能为接受者提供听力益处。对于专门为这项研究招募的BI-CI听众来说，似乎存在与处理双耳听觉信息的冲突，这产生了与预期听力益处相反的效果。这表明可能有一部分潜在的BI-CI用户，对侧干扰抵消了大部分潜在的头影益处。如果是这样的话，早期植入第二个植入耳可能会产生更大的双耳受益，这对于临床医生建议患者考虑双侧植入是重要的信息。
Bilateral cochlear implants (BI-CIs) are intended to improve sound localization and speech understanding in the presence of interfering sounds. For normal-hearing listeners, improved speech understanding in the presence of interfering sounds can be achieved with monaural head shadow and binaural unmasking. While some BI-CI listeners experience binaural unmasking under certain testing conditions, others appear to not. This study tested a group of BI-CI users with hearing histories that have been linked to poor binaural processing – early onset of deafness or long duration of deafness in just one ear. We predicted that these listeners would experience the opposite of binaural unmasking (i.e., contralateral interference) when trying to understand speech in the presence of a competing talker. Nine adult BI-CI users who were deafened early in life or had an asymmetric hearing history (e.g., a much longer duration of deafness in one ear) participated in this study. The coordinate response-measure (CRM) corpus was used to assess speech understanding for a male target talker in quiet or in the presence of one male competing talker. Experiment 1 measured binaural unmasking in a paradigm that provided no head-shadow component. The target was always presented monaurally while the interferer was presented either monaurally or diotically. Experiment 2 measured spatial release from masking in a paradigm that included both a head-shadow component and possible binaural-unmasking component. Non-individualized head-related transfer functions were used to simulate talker locations in the front or 90° to the left or right. In experiment 1, all nine listeners experienced contralateral interference (9 dB on average). Four listeners demonstrated roughly symmetric contralateral interference; five listeners experienced asymmetrical contralateral interference. In experiment 2, the listeners experienced only 1 dB of spatial release from masking on average; this small amount was possibly a result of the contralateral interference observed in experiment 1. The results were best explained by individual differences in speech understanding in quiet, which significantly correlated with the duration of deafness in the ipsilateral ear. Specifically, instances of asymmetrical contralateral interference could correspond to asymmetrical hearing histories. Bilateral cochlear implantation should provide a hearing benefit to the recipient. For the BI-CI listeners specifically recruited for this study, there seems to be a conflict with processing the auditory information across the two ears, which produced the opposite of the desired hearing benefit. This suggests that there may be a subset of potential BI-CI users for whom contralateral interference offsets much of the potential head-shadow benefit. If so, earlier implantation in the second implanted ear might have produced larger binaural benefits, which is important information for clinicians advising patients considering bilateral implantation.