语后聋人工耳蜗使用者电刺激听觉部位音调感知研究

系统地研究了人工耳蜗植入者的电刺激听觉部位音调感知,全面地探讨了部位音调感知与人工耳蜗植入者言语识别和音乐感知的关系。4位成人语后聋人工耳蜗植入者参与了该研究。通过电极音调排序测试度量植入者的部位音调感知能力。言语能力测试和音乐音高分辨测试分别用米考察植入者的言语识别和音乐感知能力。结果显示,随着电极刺激部位从蜗尖移向蜗底,所有受试者均可获得从"低"到"高"的音调感知变化,但个体差异较大。受试者的言语识别结果与其电刺激听觉部位音调感知能力相关,但受到天花板效应影响,对应关系并不明显。受试者的音乐音高分辨成绩与其电刺激听觉部位音调感知能力呈较好的对应关系。结果表明,当前人工耳蜗声音编码策略所传递的声信号特征已可使植入者获得良好的言语识别效果;且安静环境下言语识别对植入者的部位音调感知能力要求不高。但当前的声音编码策略并未能有效对音乐信号进行编码;植入者在理解音乐这类复杂声信号时,其电刺激听觉部位音调感知能力一定程度决定了其听音效果。 

Place-pitch perception in electrical hearing with post-lingual deafened cochlear implant users

The main goal of this study was to systematically investigate place-pitch perception in electrical hearing and the relative relationship between place-pitch perception ability, speech understanding and musical pitch discrimination by cochlear implant (CI) users. Electrode pitch ranking test was carried out to evaluate the place-pitch perception ability of CI users. Four post-lingual deafened CI users were recruited. They also participated in the speech recognition test and musical pitch discrimination test. Results showed that place pitch was generally ordered from apical to basal electrodes. The apical electrodes were judged lower in pitch than basal electrodes. Large individual difference was found. Comparing pitch and speech performance, the speech recognition result was relative with the place-pitch perception ability of CI users, but this relationship was limited by the ceiling effects. However, good relationship was found between musical pitch discrimination result and place-pitch ability of CI users. It indicated that the current signal processing of CI system can provide sufficient information for speech understanding but not for music perception of CI users. To a certain extent, music perception of CI users was determined by their place-pitch abilities.