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.
ABSTRACT
Frailty is an age-related condition characterized by a decline in physical capacity with an increased vulnerability to stressors. During the COVID-19 pandemic, there was considerable progression in frailty in older adults. Therefore, an online frailty check (FC) is required for continuous screening, especially acceptable to older adults. We aimed to co-design/co-develop an online FC application with FC supporters who were facilitators in a pre-existing onsite FC program in the community. It consisted of a self-assessment of sarcopenia and an 11-item questionnaire assessing dietary, physical, and social behaviors. Opinions obtained from FC supporters (median 74.0 years) were categorized and implemented. The usability was assessed using the system usability scale (SUS). For both FC supporters and participants (n = 43), the mean score was 70.2 ± 10.3 points, which implied a "marginally high" acceptability and a "good" adjective range. Multiple regression analysis showed that the SUS score was significantly correlated with onsite-online reliability, even after adjusting for age, sex, education level, and ICT proficiency (b = 0.400, 95% CI: 0.243-1.951, p = 0.013). We also validated the online FC score, which showed a significant association between onsite and online FC scores (R = 0.670, p = 0.001). In conclusion, the online FC application is an acceptable and reliable tool to check frailty for community-dwelling older adults.