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

实现了以下三个夏天：1.；衰老对语音感知的影响本研究明确了语音识别的两个相关因素及其衰老效应。一是通过信噪比和纯音平均听觉水平预测噪声环境下的语音识别性能。另一个是认知因素。我们对语速和关键词数量进行了调查，发现语速过慢会给听力带来困难，并且不会提高年轻人和老年人的语音清晰度分数。应在内存中保存一段时间的关键字的最大数量应少于3个。获得了语音公告的最大呈现水平，青年听众和老年听众在最大呈现水平上没有差异。室内声学条件下的语音传输性能预测及以火车站和机场为例研究提出了两种预测室内语音传输性能的指标。一个是语音传输指数，另一个是有用-有害比。明确了预测的计算方法和准确性。对公共空间声环境实例进行了评价。在公共场所为视障人士提供方向和位置的听觉信号。本研究探讨噪音和混响对听觉信号声音定位的影响。在噪声中，一些鸟类的歌声比“Pinpon”的声音具有更好的声音定位精度。然而，我们发现设计听觉信号的关键因素是信号的时间序列。听力测试结果表明，头部运动对声音定位非常重要，正常人和视障者对声音定位的准确性没有显著差异。

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.