Evaluation n method of aural environment and development of method for presentation of auditory signals for older persons and persons with disabilities

取得了以下三个方面的成果：1.年龄对语音感知的影响这项研究清楚地发现了两个与语音识别相关的因素及其年龄效应。一种是在噪声环境下，语音识别性能可以通过信噪比和纯音平均听力水平来预测。二是认知因素。对语速和关键词的数量进行了调查，发现语速太慢会给年轻人和老年人的听力带来困难，并且不会提高言语清晰度。关键字的最大数量应该在内存中一段时间应该少于三个。研究结果表明：1.获得了口头通知的最大呈现水平，且青年人和老年人的最大呈现水平没有差异.室内声学条件下语音传输性能的预测及车站、机场评价实例研究本研究提出了两个预测室内语音传输性能的指标。一个是言语传递指数，另一个是有害比。明确提出了计算方法和预测精度。评价了公共空间声环境实例.听觉信号提供方向和位置，以支持活动，特别是视障人士在公共场所这项研究提出了噪声和混响的声音定位的听觉信号的影响。在噪声环境中，部分鸟鸣声的定位精度优于“Pinpon”声。然而，人们发现设计听觉信号的关键因素是信号的时间序列。听力测试的结果表明，头部运动对声音定位是非常重要的，正常人和视力障碍者的声音定位精度没有显著差异。

The following three summery were achieved;1. The effect of aging on speech perception This study clearly found two factors related to speech recognition and their aging effect. One is that speech recognition performance can be predicted by signal-to-noise ratio and pure-tone averaged hearing level in noisy environment. The other is that cognitive factors. Speaking rate and number of key words were investigated and found that too slow speaking rate gives listening difficulty and doesn't improve speach intelligibility scores both for young and older listeners. The maximum number of key words which should be in memory for a while should be less than three. The maximum presentation level of spoken announcements was obtained and there is no difference of maximum presentation level between young and older listener.2. Prediction of speech transmission performance of acoustical conditions in rooms and case study of evaluation at railway stations and airports This study presents two indices to predict speech transmission performance in rooms. One is Speech Transmission Index and the other is Useful-to Detrimental ratio. Calculation methods and accuracy of predictions were clearly presented. The examples of sound environment in public spaces are evaluated.3. Auditory signals presenting directions and locations to support activities especially for visually impaired persons in public spaces This study presents the effect of noise and reverberation on sound localization of auditory signals. Some of bird's songs presented better accuracy of sound localization than "Pinpon" sound in noise. However, it was found that the key factor of designing auditory signals is time series of signal. As a result of listening tests, head movement is very important to localize a sound and there is not significant difference of accuracy of sound localization between normal person and person with visual impairment.