PDF(Pubmed)
Abstract：
The ability of individuals with visual impairment to recognize an obstacle by hearing is called \"obstacle sense\". This ability is facilitated while they are moving, though the exact reason remains unknown. This study aims to clarify which acoustical factors may contribute to obstacle sense, especially obstacle distance perception. First, we conducted a comparative experiment regarding obstacle distance localization by individuals who are blind (N = 5, five men with blindness aged 22-42 (average: 29.8)) while they were standing and walking. The results indicate that the localized distance was more accurate while walking than while standing. Subsequently, the head rotation angle while walking and acoustic characteristics with respect to obstacle distance and head rotation angle were investigated. The peaks of the absolute head rotation angle during walking ranged from 2.78° to 11.11° (average: 6.55°, S.D.: 2.05°). Regarding acoustic characteristics, acoustic coloration occurred, and spectral interaural differences and interaural intensity differences were observed in the blind participants (N = 4, four men including two blind and two control sighted persons aged 25-38 (average: 30.8)). To determine which acoustic factors contribute, we examined the threshold of changes for interaural differences in time (ITD) and intensity (IID) (N = 11, seven men and four women with blindness aged 21-35 (average: 27.4)), as well as coloration (ICD) (N = 6, seven men and a woman with blindness aged 21-38 (average: 29.9))-depending on the head rotation. Notably, ITD and IID thresholds were 86.2 μs and 1.28 dB; the corresponding head rotation angles were 23.5° and 9.17°, respectively. The angle of the ICD threshold was 6.30° on average. Consequently, IID might be a contributing factor and ICD can be utilized as the cue facilitating the obstacle distance perception while walking.
摘要：
患有视觉障碍的人通过听觉识别障碍的能力称为“障碍感”。这种能力在他们移动时得到了促进，尽管确切原因尚不清楚。本研究旨在阐明哪些声学因素可能有助于障碍感，尤其是障碍物距离感知。首先,我们进行了一项关于站立和行走时盲人（N=5，5名年龄在22-42岁之间的失明男性（平均：29.8））的障碍物距离定位的比较实验。结果表明，步行时的局部距离比站立时更准确。随后，研究了行走时的头部旋转角度以及相对于障碍物距离和头部旋转角度的声学特性。行走过程中头部绝对旋转角度的峰值范围为2.78°至11.11°（平均值：6.55°，S.D.:2.05°)。关于声学特性，发生声学着色，在盲人参与者中观察到光谱耳间差异和耳间强度差异（N=4，四名男性，包括两名盲人和两名25-38岁的对照者（平均：30.8））。为了确定哪些声学因素有贡献，我们检查了耳间时间差异（ITD）和强度（IID）的变化阈值（N=11，7名男性和4名女性，年龄为21-35（平均：27.4）），以及着色（ICD）（N=6，7名男性和1名女性，年龄为21-38（平均：29.9））-取决于头部旋转。值得注意的是,ITD和IID阈值分别为86.2μs和1.28dB；相应的磁头旋转角度分别为23.5°和9.17°，分别。ICD阈值的角度平均为6.30°。因此,IID可能是一个促成因素，并且ICD可以用作提示，以促进步行时的障碍物距离感知。
