Zheng Yunfang, Koehnke Janet, Besing Joan
Department of Communication Sciences and Disorders, Central Michigan University, Mount Pleasant, MI.
Department of Communication Sciences and Disorders, Montclair State University, Bloomfield, NJ.
Am J Audiol. 2017 Dec 12;26(4):519-530. doi: 10.1044/2017_AJA-16-0101.
This study examined the individual and combined effects of noise and reverberation on the ability of listeners with normal hearing (NH) and with bilateral cochlear implants (BCIs) to localize speech.
Six adults with BCIs and 10 with NH participated. All subjects completed a virtual localization test in quiet and at 0-, -4-, and -8-dB signal-to-noise ratios (SNRs) in simulated anechoic and reverberant (0.2-, 0.6-, and 0.9-s RT60) environments. BCI users were also tested at +8- and +4-dB SNR. A 3-word phrase was presented at 70 dB SPL from 9 simulated locations in the frontal horizontal plane (±90°), with the noise source at 0°.
BCIs users had significantly poorer localization than listeners with NH in all conditions. BCI users' performance started to decrease at a higher SNR (+4 dB) and shorter RT60 (0.2 s) than listeners with NH (-4 dB and 0.6 s). The combination of noise and reverberation began to degrade localization of BCI users at a higher SNR and a shorter RT60 than listeners with NH.
The clear effect of noise and reverberation on the performance of BCI users provides information that should be useful for refining cochlear implant processing strategies and developing cochlear implant rehabilitation plans to optimize binaural benefit for BCI users in everyday listening situations.
本研究考察了噪声和混响对听力正常者（NH）及双侧人工耳蜗植入者（BCI）言语定位能力的单独及联合影响。
6名双侧人工耳蜗植入者和10名听力正常者参与了研究。所有受试者在安静环境以及模拟无回声和混响（混响时间分别为0.2秒、0.6秒和0.9秒）环境中，以0 dB、-4 dB和-8 dB的信噪比（SNR）完成了虚拟定位测试。双侧人工耳蜗植入者还在+8 dB和+4 dB的信噪比下进行了测试。在额状水平面（±90°）的9个模拟位置上，以70 dB声压级呈现一个3词组，噪声源位于0°。
在所有条件下，双侧人工耳蜗植入者的定位能力显著低于听力正常者。与听力正常者（-4 dB和0.6秒）相比，双侧人工耳蜗植入者的表现开始下降时的信噪比更高（+4 dB），混响时间更短（0.2秒）。与听力正常者相比，噪声和混响的组合在更高的信噪比和更短的混响时间下开始降低双侧人工耳蜗植入者的定位能力。
噪声和混响对双侧人工耳蜗植入者表现的明显影响为优化人工耳蜗处理策略及制定人工耳蜗康复计划提供了有用信息，以便在日常聆听情况下为双侧人工耳蜗植入者优化双耳益处。
