Study in the Selection of Optimum Hearing Aids with the Computer and the Practical Application of the Method in the Educational Field

建立了目前常用的助听器数据库。检索项目为：频率响应编码类型、最大功率输出和最大增益。根据患者的听阈水平数据，对选择最佳助听器的几个标准进行测试，最后采用语音水平法。语音级方法是选择频率响应和增益，使平均语音频谱水平达到患者最舒适的水平。然而，在我们的方案中，引入了几个新的修改：(1)根据患者听力水平的严重程度逐步提高作为放大目标的语音水平。(2)根据患者受损的严重程度调整选择助听器时的频率权重。这是通过对严重穿孔的人的低频区域进行更重的加权来完成的。我们检查所安装的助听器的适宜性的方法也是从这项研究中得出的。检查了几种用于检测的声源，结果采用了带噪声。此外，还测量了日语的语音频谱，作为配戴助听器放大的目标。该程序实际应用于聋校和重听班的学生。结果相当好，大多数学生对助听器表示了比以前更满意的结果。配戴助听器后，频率响应几乎没有改变，但在应用其他选择标准时需要进行多次修改，现在可以满足实际教育领域配戴助听器的需求。

A data-base for hearing aids frequently used today was constructed. The items for retrieval are: the coded type of frequency response, maximum power output and maximum gain.Several criterion for selecting the optimum hearing aid, based on the data of hearing threshold level of the patient, were tested and finally the "speech level method" was adopted. The speech level method is to select the frequency response and gain that bring the mean speech spectrum level to the most comfortable level of the patient. However, in our program, several new modification were introduced.(1) The speech level as the target of amplification is gradually raised according to the severeness of the hearing level of the patient.(2) The weight of the frequency when a hearing aid is selected is adjusted to the severeness of the impairment of the patient. This is done by the low frequency region being more heavily weighted for the severely-impiared person.Our method for checking the suitability of the hearing aid fitted was also derived from this study. Several sound sources for checking were examined and band-noise was adopted as a result. Also the speech spectrum of Japanese was measured as the target of the amplification for fitting hearing aids.The program was actually applied to pupils enrolled in the schools for the deaf and the classes for the hard of hearing. The result was fairly good so that most of the pupils expressed more satisfication than with their previous hearing aid. There was almost no modification of the frequency response after fitting of the hearing aids, though several modifications were needed when the other selection criteria were applied.Now we can meet the demands of fitting the hearing aid in the actual educational field.