Development of the three dimensional auditory space reproduction system suited to the multi-modal environment

当我们识别外界时，我们使用各种感官信息。这种机制是众所周知的多模态信息处理和开发新的人机界面非常重要。本文着重研究了与三维听觉空间知觉有关的多通道信息加工。本研究旨在探讨听觉空间知觉与躯体信息的关系。在第一个实验中，我们利用虚拟声音，实验性地研究了头部运动对声音定位的影响。在这个实验中，一些HRTF（头部相关的传递函数）被用来产生虚拟声音。这些HRTF从听者的原始HRTF系统地改变。结果表明，在所有的HRTF上，通过收听者的头部运动，声音定位的准确性得到了提高。在接下来的实验中，我们研究了压力分割场（PDR）对双耳声音合成的影响。我们通过使用七个耳机来测量PDR。结果表明，PDR取决于耳机和听者的声学特性。此外，还通过听音实验验证了均衡PDR对声音定位的影响，利用本研究获得的知识，我们建立了一个精确的三维空间听觉系统。利用该系统进行的听音实验结果表明，该系统能够准确地再现三维听觉空间。

When we recognize outside, we use various sensory information. This mechanism is well-known as a multi-modal information process and very crucial for developing new man-machine interfaces. We have focused on the multi-modal information process concerned with three dimensional auditory space perception. In this study, we investigated the relationship between auditory space perception and somatic information. Moreover, we developed the three dimensional auditory space reproduction system suited to the multi-modal environment.In the first experiment, we experimentally examined the effect of the head movement concerning sound localization by using virtual sound. In this experiment, some HRTFs (Head-Related Transfer Functions) were used to generate virtual sound. These HRTFs were systematically changed from the listener's original one. The results showed that the accuracy of sound localization improved by listener's head movement on all HRTFs. This suggests that somatic information is quite important for sound localization.In the next experiment, the influence of the PDR (Pressure Division Field) on binaural sound synthesis was investigated. we measured PDR by using seven headphones. The results showed that the PDR depended on both the headphone and listener's acoustical characteristics. Moreover the effects of equalizing PDR on sound localization was verified by listening experiment.Using this knowledge obtained in this study, we created a precise three dimensional spatial hearing system. As the results of listening test by using this system, we showed that this system was useful for reproduction 3 dimensional auditory space accurately.