Behavioral and Event-Related Potential Studies on Mandarin Tone Perception through Cochlear Implant Processing

• Main Authors: Chen, Man-Chun, 陳曼君
• Other Authors: 郭于靚
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/67504579202733271011

碩士 === 臺北市立大學 === 特殊教育學系 === 104 === There have been over 1500 cochlear implants (CI) users in Taiwan. Mandarin Chinese is the main language and tone in Mandarin Chinese plays an important role and provide different semantic knowledge; therefore, it is reasonable to explore how CI users perceive tone and the factors that influence users to distinguish tone. Moreover, it is not perfect to transmit the tone in language because of the limitation of spectral resolution in CI. Spectral resolution of cochlear implants is mainly determined by the number of channels, thus, increasing the number of channels may improve spectral resolution and enhance the ability to deliver the tone. In addition to the analysis of spectral resolution, many foreign scholars also explore the related factors of distinguishing tone, including the identification of the paired tone and the exploration of acoustic analyses, such as, fundamental frequency, amplitude envelope, and the length of time. Thus, this study aims to investigate how the perception of tones in Chinese is affected by the speech processing of CI. The research method involved behavior reaction and Event-Related Potential (ERP). In study one, 27 normal adults participated in the study and this study investigated the MMN performance of normal hearing adults based on the contrast of natural speech sounds and the sounds of using CI when changing different channels, including 1, 4, 8, and 32 channels. The results showed that 1-channel simulations resulted in P-MMR response and 4-channel simulations could not evoke MMN response; however, the number of channels increasing to 8 evoked MMN response. On the other hand, the results of MMN response were similar after changing to 32 channels. The increasing of channels could not enhance MMN response as expected. In study two, 9 adults with normal hearing and 4 cochlear implants users participated in the study and the study explored the influence on adults with normal hearing and CI users according to the paired tone, the amount of acoustic analyses, and single and double words. The results indicated that adults with normal hearing were not affected by the paired tone, the amount of acoustic analyses, and single and double words. However, there was a great variability of the performance of CI users when distinguishing tone in Chinese. Most of all, the difference of the paired tone could influence the performance of CI users.