Everhardt Marita K, Sarampalis Anastasios, Coler Matt, Başkent Deniz, Lowie Wander
Center for Language and Cognition Groningen, University of Groningen, The Netherlands.
Department of Otorhinolaryngology, University Medical Center Groningen, The Netherlands.
Ear Hear. 2020 Sep/Oct;41(5):1092-1102. doi: 10.1097/AUD.0000000000000863.
This study quantitatively assesses how cochlear implants (CIs) and vocoder simulations of CIs influence the identification of linguistic and emotional prosody in nontonal languages. By means of meta-analysis, it was explored how accurately CI users and normal-hearing (NH) listeners of vocoder simulations (henceforth: simulation listeners) identify prosody compared with NH listeners of unprocessed speech (henceforth: NH listeners), whether this effect of electric hearing differs between CI users and simulation listeners, and whether the effect of electric hearing is influenced by the type of prosody that listeners identify or by the availability of specific cues in the speech signal.
Records were found by searching the PubMed Central, Web of Science, Scopus, Science Direct, and PsycINFO databases (January 2018) using the search terms "cochlear implant prosody" and "vocoder prosody." Records (published in English) were included that reported results of experimental studies comparing CI users' and/or simulation listeners' identification of linguistic and/or emotional prosody in nontonal languages to that of NH listeners (all ages included). Studies that met the inclusion criteria were subjected to a multilevel random-effects meta-analysis.
Sixty-four studies reported in 28 records were included in the meta-analysis. The analysis indicated that CI users and simulation listeners were less accurate in correctly identifying linguistic and emotional prosody compared with NH listeners, that the identification of emotional prosody was more strongly compromised by the electric hearing speech signal than linguistic prosody was, and that the low quality of transmission of fundamental frequency (f0) through the electric hearing speech signal was the main cause of compromised prosody identification in CI users and simulation listeners. Moreover, results indicated that the accuracy with which CI users and simulation listeners identified linguistic and emotional prosody was comparable, suggesting that vocoder simulations with carefully selected parameters can provide a good estimate of how prosody may be identified by CI users.
The meta-analysis revealed a robust negative effect of electric hearing, where CIs and vocoder simulations had a similar negative influence on the identification of linguistic and emotional prosody, which seemed mainly due to inadequate transmission of f0 cues through the degraded electric hearing speech signal of CIs and vocoder simulations.
本研究定量评估人工耳蜗（CI）及人工耳蜗的声码器模拟如何影响非声调语言中语言韵律和情感韵律的识别。通过荟萃分析，探究了与未处理语音的正常听力（NH）听众（以下简称：NH听众）相比，CI使用者和声码器模拟的正常听力（NH）听众（以下简称：模拟听众）识别韵律的准确程度，电听觉的这种影响在CI使用者和模拟听众之间是否存在差异，以及电听觉的影响是否受听众识别的韵律类型或语音信号中特定线索的可用性影响。
通过在PubMed Central、Web of Science、Scopus、Science Direct和PsycINFO数据库（2018年1月）中搜索“人工耳蜗韵律”和“声码器韵律”等检索词来查找记录。纳入了以英文发表的报告实验研究结果的记录，这些研究比较了CI使用者和/或模拟听众对非声调语言中语言和/或情感韵律的识别与NH听众（涵盖所有年龄段）的识别情况。符合纳入标准的研究进行了多层次随机效应荟萃分析。
28篇记录中报告的64项研究纳入了荟萃分析。分析表明，与NH听众相比，CI使用者和模拟听众在正确识别语言和情感韵律方面准确性较低，情感韵律的识别受电听觉语音信号的影响比语言韵律更大，并且基频（f0）通过电听觉语音信号的低传输质量是CI使用者和模拟听众韵律识别受损的主要原因。此外，结果表明CI使用者和模拟听众识别语言和情感韵律的准确性相当，这表明精心选择参数的声码器模拟可以很好地估计CI使用者如何识别韵律。
荟萃分析揭示了电听觉的显著负面影响，其中CI和声码器模拟对语言和情感韵律的识别具有类似的负面影响，这似乎主要是由于f0线索通过CI和声码器模拟的退化电听觉语音信号传输不足所致。
