Study on temporal factors in word discrimination ability of elder citizens and hearing aid fitting method for digital hearing aids

提出了一种新的助听器评估方法--变语率测听法（VSRA）。VSRA是根据日本听力学会授权的日语言语测听法新创建的。我们有时会看到老年人在快速讲话时有很大的单词辨别困难。然而，普通言语测听并不能揭示听力障碍者词辨能力的时间因素。由于VSRA，我们可以比较几个性能强度曲线从不同的语速语音测听，对每个患者的听觉系统的影响，由快速或慢速的语音速率可以很容易地确定。本文应用VSRA技术，考虑听觉系统的时间因素，对36名听力障碍者进行了三种信号处理和验配方式的主助听器的助听效果评价。然后使用VSRA对新开发的便携式多功能数字助听器进行助听器评估，该助听器具有两种类型的信号处理和模拟助听器，已被听力受损患者使用。因此，VSRA是有用的助听器的评估，特别是，当普通正常的言语速率测听不提供显着差异的单词辨别分数的情况下。此外，使用VSRA显示，幅度压缩是更有效的改善字的歧视比线性放大。

A new hearing aid evaluation method using variable-speech-rate audiometry (VSRA) was developed. VSRA was newly created based on the Japanese speech audiometry authorized by the Japan Audiological Society. We sometimes see elder citizens who have great word discrimination difficulties for fast speech. However the ordinary speech audiometry can not reveal a temporal factor in word dicrimination ability of the hearing impaired. Since, with VSRA, we can compare several performance-intensity curves obtained from different speech-rate speech audiometries, the impact on the auditory system of each patient by the fast or slow speech rate could be easily determined. Taking the temporal factor of the auditory systems into cosideration by using VSRA, hearing aid evaluation was performed for a master hearing aid with three types of signal processings and fittings for 36 hearing impaired subjects. Then hearing aid evaluation was performed using VSRA for a newly developed portable multi-function digital hearing aid with two types of signal processing and analog hearing aids which had been used by hearing-impaired patients. As a result, VSRA was useful for hearing aid evaluation, in particular, for cases when ordinary normal speech rate audiometry does not provide a significant diffence in word discrimination scores. In addition, using VSRA revealed that amplitude compression is more effective for improvement of word discrimination than linear amplification.