Enhancing Tone Recognition for Cochlear Implant Users

描述(申请人提供)：这项研究的总体长期目标是为讲声调语言的人工耳蜗用户开发新的语音处理策略。为了改善人工耳蜗中的声调语言感知，本申请的重点是增强电子听力中声调信息的传输，因为声调信息对于声调语言中的语音感知是至关重要的，并且当前的人工耳蜗器不能为用户提供足够的声调信息。提出了三个实验来增强人工耳蜗术中不同音调相关的信息。具体目的1是研究预处理器修改单音节的总幅度包络，以更好地接近其基频轮廓，是否可以提高人工耳蜗术中的音调识别能力。初步研究表明，这种幅度包络修改显著提高了4通道人工耳蜗声学模拟中的汉语声调识别，而不会对元音识别产生不利影响。将在不同幅度包络修改的情况下测试说声调语言的人工耳蜗者的声调和元音识别，以寻找在声调识别改善和可能的元音识别减少之间的最佳权衡。具体目的2是研究人工耳蜗术受者在非人工耳内佩戴助听器的情况下，在语音形状噪声或语音杂音中的声调语言知觉。初步研究表明，在语音噪声中，随着低频信息的增加，汉语句子识别能力显著增强；具体地说，当低频信息为500赫兹时，这种句子识别能力的提高主要是由于声调识别的改善。作为对侧电听力的补充，将研究助听器恢复低频声学听力的频率范围和信号电平的影响。具体目的3是研究在人工耳蜗术中，能否使用宽双极刺激模式产生的超低音感觉来有效地编码音调信息。使用4声道人工耳蜗声学模拟的初步研究表明，随着基音范围内额外频率通道数量的增加，汉语声调识别显著增强。本课程将探讨混合刺激模式在人工耳蜗术中用于声调语言语音处理的装置实现与应用。

DESCRIPTION (provided by applicant): The overall long-term goal of this research is to develop novel speech processing strategies for cochlear implant users speaking tonal languages. In attempt to improve tonal language perception in cochlear implants, the present application focuses on enhancing the transmission of tonal information in electric hearing, because tonal information is crucial for speech perception in tonal languages, and that current cochlear implants do not provide sufficient tonal information for users. Three experiments are proposed to enhance different tone- related information in cochlear implants. Specific Aim 1 is to investigate whether pre-processors modifying single syllable's overall amplitude envelope, to better resemble its fundamental frequency contour, can enhance tone recognition in cochlear implants. Pilot studies revealed that such amplitude envelope modifications significantly improved Chinese tone recognition in 4-channel cochlear implant acoustic simulations, without adversely affecting vowel recognition. Tone and vowel recognition of tonal-language-speaking cochlear implant users will be tested under different amounts of such amplitude envelope modifications, to search for the best trade-off between tone recognition improvement and possible vowel recognition decrease. Specific Aim 2 is to investigate tonal language perception in speech-shaped noise or speech-babble noise with cochlear implant recipients using a hearing aid in the non-implanted ear. Pilot studies, using acoustic simulations of a cochlear implant with a hearing aid, showed that Chinese sentence recognition in speech-shaped noise was significantly enhanced as more low frequency information was added; specifically, such sentence recognition enhancement was mostly due to better tone recognition when the low frequency information was 500 Hz. The effects of frequency range and signal level of the low frequency acoustic hearing restored by a hearing aid, as a complement to the contra-lateral electric hearing, will be investigated. Specific Aim 3 is to investigate whether tonal information can be effectively encoded using extra low pitch sensations produced by wide bipolar stimulation modes in cochlear implants. Pilot studies using 4-channel cochlear implant acoustic simulations revealed that Chinese tone recognition was significantly enhanced as the number of extra frequency channels in the pitch range was increased. Device implementation and applications of mixed stimulation modes for tonal language speech processing in cochlear implants will be investigated.