Utilization of auditory perceptions of sounds and silent objects for orientation and mobility by visually-impaired people

The visually-impaired people have the difficulty on perceive the largeness of a space and objects existed in a space by means of visual information. Particularly auditory-trained visually-impaired people can recognize 3-D spatial information with environmental sounds. However, systematic learning method of auditory training for acquired visually-impaired is not established sufficiently because the self-experience of the visually-impaired people is the main reason of ability acquisition in the actual environment because they do not have enough information about moving in the real environment. In this paper, the authors aim at demonstrating moving situations and moving needs of the visually-impaired, for example, which acoustical factors can be used in some living situation, what kind of environmental situation they think it difficult to perceive silent objects and what kind of aid they need. Results indicated following facts: Totally visually-impaired people tend to get more spatial information from auditory than not-totally visually-impaired people. Regarding available auditory cues, items of rotating head in order to listen carefully to environmental sound, and hitting floors stronger by a white cane or foot for voluming up reflected or reverberated sounds were much selected by the totally visually-impaired participants who can perceive obstacles with auditory information. Result of question about conventional devices indicated that most totally visually-impaired participants selected electrical sounding device informing obstacle distance, while most not-totally visually-impaired participants selected vibrating device informing the distance of walls or doors and tactually-stimulated device informing obstacle distance.