Fowler Jennifer R, Eggleston Jessica L, Reavis Kelly M, McMillan Garnett P, Reiss Lina A J
J Speech Lang Hear Res. 2016 Feb;59(1):99-109. doi: 10.1044/2015_JSLHR-H-15-0247.
The objective was to determine whether speech perception could be improved for bimodal listeners (those using a cochlear implant [CI] in one ear and hearing aid in the contralateral ear) by removing low-frequency information provided by the CI, thereby reducing acoustic-electric overlap.
Subjects were adult CI subjects with at least 1 year of CI experience. Nine subjects were evaluated in the CI-only condition (control condition), and 26 subjects were evaluated in the bimodal condition. CIs were programmed with 4 experimental programs in which the low cutoff frequency (LCF) was progressively raised. Speech perception was evaluated using Consonant-Nucleus-Consonant words in quiet, AzBio sentences in background babble, and spondee words in background babble.
The CI-only group showed decreased speech perception in both quiet and noise as the LCF was raised. Bimodal subjects with better hearing in the hearing aid ear (< 60 dB HL at 250 and 500 Hz) performed best for words in quiet as the LCF was raised. In contrast, bimodal subjects with worse hearing (> 60 dB HL at 250 and 500 Hz) performed similarly to the CI-only group.
These findings suggest that reducing low-frequency overlap of the CI and contralateral hearing aid may improve performance in quiet for some bimodal listeners with better hearing.
本研究旨在确定对于双耳佩戴不同助听设备的听众（即一只耳朵使用人工耳蜗[CI]，对侧耳朵使用助听器），去除CI提供的低频信息，从而减少声电重叠，是否能改善言语感知。
研究对象为成年人工耳蜗使用者，且至少有1年的人工耳蜗使用经验。9名受试者在仅使用人工耳蜗的条件下（对照条件）接受评估，26名受试者在双耳佩戴不同助听设备的条件下接受评估。人工耳蜗被设置了4个实验程序，其中低截止频率（LCF）逐渐提高。使用安静环境下的辅音-元音-辅音单词、背景嘈杂声中的AzBio句子以及背景嘈杂声中的扬扬格单词来评估言语感知。
仅使用人工耳蜗的组在安静环境和噪声环境下，随着低截止频率的提高，言语感知能力均下降。在助听器佩戴耳听力较好（250Hz和500Hz时<60dB HL）的双耳佩戴不同助听设备的受试者中，随着低截止频率的提高，在安静环境下对单词的识别表现最佳。相比之下，在助听器佩戴耳听力较差（250Hz和500Hz时>60dB HL）的双耳佩戴不同助听设备的受试者，其表现与仅使用人工耳蜗的组相似。
这些研究结果表明，减少人工耳蜗与对侧助听器的低频重叠，可能会改善一些听力较好的双耳佩戴不同助听设备的听众在安静环境下的表现。
