Kansei evaluation of object-based three-dimensional sound for visual impairments

Currently, visually impaired people find it difficult to use mobility support facilities because they depend on properties of the ambient environment, such as ambient sound and snow cover. Furthermore, people who became visually impaired in later life also find it difficult to use these facilities. Therefore, in this study, we aimed to develop a walking guidance system, using three-dimensional (3D) sound, that is not influenced by the surrounding environment and is easy to use. We verified the characteristics of the guidance sound produced by 3D sound. This system was implemented with a head-mounted display that is capable of producing 3D sound. In a visual restriction environment, blindfolded participants were asked to indicate toward a real or 3D guiding sound with two conditions: With head fixed or free, and using a tweet-like or water sound. We also collected subjective evaluations of the sounds. As a result, we found that a stationary sound including frequency components in a wide band, like a water sound, was able to be localized with a higher accuracy than a tweet-like sound, and was suitable as a guidance sound, according to subjective evaluations.