Kressner Abigail A, Westermann Adam, Buchholz Jörg M, Rozell Christopher J
National Acoustic Laboratories, Australian Hearing, 16 University Avenue, Macquarie University, New South Wales 2109, Australia.
School of Electrical and Computer Engineering, 777 Atlantic Drive Northwest, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
J Acoust Soc Am. 2016 Feb;139(2):800-10. doi: 10.1121/1.4941567.
It has been shown that intelligibility can be improved for cochlear implant (CI) recipients with the ideal binary mask (IBM). In realistic scenarios where prior information is unavailable, however, the IBM must be estimated, and these estimations will inevitably contain errors. Although the effects of both unstructured and structured binary mask errors have been investigated with normal-hearing (NH) listeners, they have not been investigated with CI recipients. This study assesses these effects with CI recipients using masks that have been generated systematically with a statistical model. The results demonstrate that clustering of mask errors substantially decreases the tolerance of errors, that incorrectly removing target-dominated regions can be as detrimental to intelligibility as incorrectly adding interferer-dominated regions, and that the individual tolerances of the different types of errors can change when both are present. These trends follow those of NH listeners. However, analysis with a mixed effects model suggests that CI recipients tend to be less tolerant than NH listeners to mask errors in most conditions, at least with respect to the testing methods in each of the studies. This study clearly demonstrates that structure influences the tolerance of errors and therefore should be considered when analyzing binary-masking algorithms.
研究表明，对于使用理想二元掩蔽（IBM）的人工耳蜗（CI）植入者，可懂度能够得到提高。然而，在无法获得先验信息的现实场景中，必须对IBM进行估计，而这些估计不可避免地会包含误差。尽管已经针对听力正常（NH）的听者研究了非结构化和结构化二元掩蔽误差的影响，但尚未对CI植入者进行研究。本研究使用通过统计模型系统生成的掩蔽对CI植入者评估这些影响。结果表明，掩蔽误差的聚类会大幅降低对误差的容忍度，错误地去除目标主导区域对可懂度的损害可能与错误地添加干扰主导区域一样大，并且当两种误差同时存在时，不同类型误差的个体容忍度可能会发生变化。这些趋势与NH听者的趋势一致。然而，混合效应模型分析表明，在大多数情况下，CI植入者对掩蔽误差的容忍度往往低于NH听者，至少就每项研究中的测试方法而言是这样。本研究清楚地表明，结构会影响对误差的容忍度，因此在分析二元掩蔽算法时应予以考虑。
