神经网络在人工耳蜗植入儿童声调发声评估中的应用

The application of artificial neural network on the assessment of lexical tone production of pediatric cochlear implant users

目的 了解以普通话为母语的语前聋人工耳蜗植入儿童在普通话声调发声上存在的问题并探索影响其声调发声能力的潜在因素,对基于计算机技术进行声调发声的特征提取和自动化判别的可行性进行实验论证,以期对此类儿童的术后声调发声康复提供指导. 方法 278例语前聋单侧人工耳蜗植入儿童和170名年龄相仿的听力正常儿童参加了本项研究.对受试儿童的声调发声样本进行录音,在MATLAB平台上对每个受试儿童的每个发声音节进行基频提取并手动纠偏.构建人工神经网络,加以训练后对受试儿童的基频数据进行判读并分析结果.利用MATLAB统计工具对所得结果进行统计分析. 结果 人工耳蜗植入儿童的声调发声准确率（58.8%）明显低于同龄正常儿童（91.5%）,且个体差异较大.二声和三声的发声准确率较一声和四声低,人工耳蜗植入儿童的声调发声出错时最易被判读成一声.人工耳蜗植入儿童声调发声准确率与植入年龄呈负相关（r=-0.215, P=0.003）,与设备使用时长呈正相关（r=0.203, P=0.005）.年龄是影响正常听力儿童声调发声能力的决定因素之一. 结论 对于确诊为重度至极重度聋的儿童,早期植入人工耳蜗并长期坚持使用有利于其声调能力的发展.人工神经网络可作为监测聋儿声调发声能力发展及康复效果的方便且可靠的评估手段.

Objective The present study was carried out to explore the tone production ability of the Mandarin-speaking children with cochlear implants （CI） by using an artificial neural network model and to examine the potential contributing factors underlining their tone production performance.The results of this study might provide useful guidelines for post-operative rehabilitation processes of pediatric CI users.Methods Two hundred and seventy-eight prelingually deafened children who received unilateral CI participated in this study.As controls, 170 similarly-aged children with normal hearing （NH） were recruited.A total of 36 Chinese monosyllabic words were selected as the tone production targets.Vocal production samples were recorded and the fundamental frequency （F0） contour of each syllable was extracted using an auto-correlation algorithm followed by manual correction.An artificial neural network was created in MATLAB to classify the tone production.The relationships between tone production and several demographic factors were evaluated.Results Pediatric CI users produced Mandarin tones much less accurately than did the NH children （58.8% vs.91.5% correct）.Tremendous variability in tone production performance existed among the CI children.Tones 2 and 3 were produced less accurately than tones 1 and 4 for both groups.For the CI group, all tones when in error tended to be judged as tone 1.The tone production accuracy was negatively correlated with age at implantation and positively correlated with CI use duration with correlation coefficients （r） of-0.215 （P=0.003） and 0.203 （P=0.005）, respectively.Age was one of the determinants of tonal ability for NH children.Conclusions For children with severe to profound hearing loss, early implantation and persistent use of CI are beneficial to their tone production development.Artificial neural network is a convenient and reliable assessment tool for the development of tonal ability of hearing-impaired children who are in the rehabilitation processes that focus on speech and language expression.