Medical University of Graz, Department of Ophthalmology, Graz, Austria.
Medical University of Graz, Institute for Medical Informatics, Statistics and Documentation, Graz, Austria.
PLoS One. 2018 Apr 26;13(4):e0196156. doi: 10.1371/journal.pone.0196156. eCollection 2018.
This study's purpose was to analyze and quantify the impact of auditory information loss versus information gain provided by electronic travel aids (ETAs) on navigation performance in people with low vision. Navigation performance of ten subjects (age: 54.9±11.2 years) with visual acuities >1.0 LogMAR was assessed via the Graz Mobility Test (GMT). Subjects passed through a maze in three different modalities: 'Normal' with visual and auditory information available, 'Auditory Information Loss' with artificially reduced hearing (leaving only visual information), and 'ETA' with a vibrating ETA based on ultrasonic waves, thereby facilitating visual, auditory, and tactile information. Main performance measures comprised passage time and number of contacts. Additionally, head tracking was used to relate head movements to motion direction. When comparing 'Auditory Information Loss' to 'Normal', subjects needed significantly more time (p<0.001), made more contacts (p<0.001), had higher relative viewing angles (p = 0.002), and a higher percentage of orientation losses (p = 0.011). The only significant difference when comparing 'ETA' to 'Normal' was a reduced number of contacts (p<0.001). Our study provides objective, quantifiable measures of the impact of reduced hearing on the navigation performance in low vision subjects. Significant effects of 'Auditory Information Loss' were found for all measures; for example, passage time increased by 17.4%. These findings show that low vision subjects rely on auditory information for navigation. In contrast, the impact of the ETA was not significant but further analysis of head movements revealed two different coping strategies: half of the subjects used the ETA to increase speed, whereas the other half aimed at avoiding contacts.
本研究旨在分析和量化听觉信息损失与电子助行器（ETA）提供的信息增益对低视力人群导航性能的影响。通过 Graz 移动测试（GMT）评估了 10 名受试者（年龄：54.9±11.2 岁）的导航性能，这些受试者的视力优于 1.0 LogMAR。受试者以三种不同模式通过一个迷宫：“正常”模式，即提供视觉和听觉信息；“听觉信息损失”模式，即人为降低听力（仅保留视觉信息）；以及“ETA”模式，即基于超声波的振动 ETA，从而提供视觉、听觉和触觉信息。主要性能指标包括通过时间和接触次数。此外，头部跟踪用于将头部运动与运动方向相关联。当将“听觉信息损失”与“正常”进行比较时，受试者需要更多的时间（p<0.001），接触次数更多（p<0.001），相对视角更高（p = 0.002），且定向丧失的百分比更高（p = 0.011）。当将“ETA”与“正常”进行比较时，唯一显著的差异是接触次数减少（p<0.001）。本研究提供了客观、可量化的衡量方法，用于评估听力下降对低视力受试者导航性能的影响。所有指标均显示“听觉信息损失”的显著影响；例如，通过时间增加了 17.4%。这些发现表明，低视力受试者依赖听觉信息进行导航。相比之下，ETA 的影响并不显著，但对头动的进一步分析揭示了两种不同的应对策略：一半的受试者使用 ETA 来提高速度，而另一半则旨在避免接触。
