Zwolan T A, Collins L M, Wakefield G H
Department of Otolaryngology, University of Michigan, Ann Arbor 48109-0312, USA.
J Acoust Soc Am. 1997 Dec;102(6):3673-85. doi: 10.1121/1.420401.
This study investigated the relationship between electrode discrimination and speech recognition in 11 postlingually deafened adult cochlear implant subjects who were implanted with the Nucleus/Cochlear Corporation multichannel device. The discriminability of each electrode included in a subject's clinical map was measured using adaptive and fixed-level discrimination tasks. Considerable variability in electrode discriminability was observed across subjects. Two subjects could discriminate all electrodes, and discrimination performance by the remaining nine subjects varied from near perfect to very poor. In these nine subjects, the results obtained from the discrimination tasks were used to create a map that contained only discriminable electrodes, and subjects' performance on speech recognition tasks using this experimental map was measured. Four different speech recognition tests were administered: a nine-choice closed-set medial vowel recognition task, a 14-choice closed-set medial consonant recognition task, the NU6 Monosyllabic Words Test [T. W. Tillman and T. Carhart, Tech. Rep. No. SAM-TR-66-55, USAF School of Aerospace Medicine, Brooks Air Force Base, Texas (1966)] scored for both words and phonemes correct, and the Central Institute for the Deaf (CID) Everyday Sentences test [H. Davis and S. R. Silverman, Hearing and Deafness (Holt, Rinehart, and Winston, New York, 1978)]. Seven of the nine subjects tested with the experimental map showed significant improvement on at least one speech recognition measure, even though the experimental map contained fewer electrodes than the original map. Three subjects' scores improved significantly on the CID Everyday Sentences test, three subjects' scores improved significantly on the NU6 Monosyllabic Words test, and five subjects' scores improved significantly on the NU6 Monosyllabic Words test scored for phonemes correct. None of the subjects' scores improved significantly on either the vowel or consonant tests. No significant correlation was observed between electrode discrimination ability and speech recognition scores or between electrode discrimination ability and improvement in speech recognition scores when programmed with the experimental map. The results of this study suggest that electrode discrimination tasks may be used to improve speech recognition of some cochlear implant subjects, and that each electrode site does not necessarily provide perceptually distinct information.
本研究调查了11名语后聋成年人工耳蜗植入者的电极辨别能力与言语识别之间的关系，这些受试者植入的是科利耳公司的Nucleus多通道装置。使用自适应和固定水平辨别任务测量受试者临床图谱中每个电极的辨别能力。观察到受试者之间电极辨别能力存在相当大的差异。两名受试者能够辨别所有电极，其余九名受试者的辨别表现从接近完美到非常差不等。在这九名受试者中，辨别任务的结果被用于创建一个仅包含可辨别的电极的图谱，并测量受试者使用该实验图谱进行言语识别任务时的表现。进行了四项不同的言语识别测试：一项九选封闭式中元音识别任务、一项十四选封闭式中辅音识别任务、对单词和音素正确得分的NU6单音节词测试[T. W. 蒂尔曼和T. 卡哈特，技术报告编号SAM - TR - 66 - 55，美国空军航空航天医学院，得克萨斯州布鲁克斯空军基地（1966年）]，以及中央聋人研究所（CID）日常句子测试[H. 戴维斯和S. R. 西尔弗曼，《听力与耳聋》（霍尔特、莱因哈特和温斯顿出版社，纽约，1978年）]。使用实验图谱测试的九名受试者中有七名在至少一项言语识别指标上有显著改善，尽管实验图谱中的电极比原始图谱少。三名受试者在CID日常句子测试中的得分显著提高，三名受试者在NU6单音节词测试中的得分显著提高，五名受试者在按音素正确得分的NU6单音节词测试中的得分显著提高。没有受试者在元音或辅音测试中的得分显著提高。当使用实验图谱编程时，未观察到电极辨别能力与言语识别得分之间或电极辨别能力与言语识别得分改善之间存在显著相关性。本研究结果表明，电极辨别任务可用于改善一些人工耳蜗植入受试者的言语识别，并且每个电极部位不一定提供感知上不同的信息。
