A study on the development of a high-performance digital hearing aid and the method of its fitting

将补偿响度招募的算法安装在为本研究定制的便携式数字助听器中，并在日常生活中评估其性能。对于较低的输入电平，将响度补偿函数设置为线性，从而实现谱减法以抑制环境或背景噪声。虽然数字助听器在其特性上具有灵活性的优点，但其配戴往往需要较长的时间。在此基础上，研究了如何有效准确地估计响度补偿函数。研究结果表明，细分一步分类标度法是目前研究的最佳方法。在此基础上，测量了100多名听力受损者的响度补偿函数，并将这些补偿函数与听力受损者进行了拟合。在日常生活中，使用配备的数字助听器进行了长时间的现场测试。在安静的环境下听广播/电视，在安静和嘈杂的环境中少数人的谈话，在很多人之间的谈话，在街上听讲话，评价自己发出的声音的质量等情况下，听众以7个类别来评估助听器的性能。结果表明，在所有情况下，新型助听器的性能都明显优于传统助听器。

The algorithm compensating for loudness recruitment was installed in portable digital hearing aids that were custom-made for this study, and its performance was evaluated in daily lives. The loudness compensation function was set to be linear for lower input levels, so that spectral subtraction was achieved to suppress environmental or background noise. Though digital hearing aids have the merit of flexibility in their characteristics, it often takes relatively long time for fitting. Thus, methods for estimating accurate loudness-compensation function efficiently were also studied. As the result of the study, it has been shown that the subdivided one-step categorical scaling method is the best method for the present purpose.On the basis of these results, loudness compensation functions were measured for more than one hundred impaired-listeners, and the fitting procedure was carried out with those functions to the impaired. Long-time field tests with the fitted digital hearing aids were conducted by the impaired in their daily lives. The listeners evaluated performance of the hearing aids in a scale of seven categories for some situations such like listening to radio/television in quiet, conversation among a few persons in quiet and in noisy environment, conversation among great numbers of people, listening to speech on the street, appraisal of the quality of self-uttered voice, and so on. The results show that the performance of the new hearing aids are significantly better than those achieved by conventional hearing aids in all the situations.