Perception and Navigation in the Absence of Vision: Developing Assistive Technologies for Environmental Awareness in the Blind

Spatial navigation allows people to navigate their surroundings efficiently, and it is one of the most important aspects of daily life. To understand the spatial navigation of blind people, my PhD focused on cognitive processes that underlie the navigation of blind and visually impaired people, paying special attention to auditory perception, path integration, and environmental learning. Moreover, my PhD also looks at the multisensory mechanism that helps efficient spatial navigation, which enhances our knowledge of the perceptual and cognitive strategies used by blind and visually impaired people to navigate their surroundings. Additionally, to increase the spatial awareness of blind and visually impaired people, my doctorate study played a role in creating assistive technologies for the navigation of blind people. In order to achieve the aims, we recruited an adult population of both blind and blindfolded sighted participants for behavioral trials. To see the role of unisensory feedback in the spatial navigation of blind people, we used a triangle completion task. To understand the impact of multisensory cues, we combined different sensory cues to see how blind people perceive them and how they affect the path integration abilities of people without vision. Moreover, we carried out extensive research on auditory perception, looking at how spatial navigation of people without vision was influenced by white noise and binaural audio feedback. Furthermore, to improve the navigational abilities of both indoor and outdoor environments, we created assistive technologies for blind and visually impaired people. A novel bus route and destinations algorithm was developed for a better understanding of the transport system. In addition to this, a navigational aid was developed with an advanced Vision Language Model (VLM) to provide a thorough environmental description to blind and visually impaired people. The aid includes a mobile application, a cane with a Bluetooth button, and bone-conduction headphones to obtain spatial signals without impairing environmental awareness. The research on unisensory feedback effects suggests that guidance is not the only cue that helps in better navigation, but there are underlying mechanisms that help blind people encode their surroundings when they are being guided. Moreover, it has been demonstrated that multisensory cues improve spatial perception more successfully than unisensory cues alone because a greater number of sensory channels help in better perception of the environment. According to the study’s investigation into auditory perception, white noise greatly facilitates spatial navigation by boosting memory and attention, which in turn improves performance. In contrast, blind people performed similarly in spatialized and non-spatialized auditory situations, according to research on binaural audio feedback, which showed no significant effect on spatial navigation. The studies on assistive technologies achieved promising results. The novel algorithm of bus assistance achieved an accuracy of 95\% in the detection of bus routes and destinations. Similarly, the development of navigational aid showed a potential for wide acceptance by the blind community. More than 90\% of participants showed satisfaction with the developed navigational device, indicating encouraging outcomes. The device’s potential to improve visually impaired people’s everyday mobility and independence is shown by its outstanding accuracy and user satisfaction ratings. The incorporation of bone-conduction auditory feedback was especially well-received since it made navigation smooth and easy while enabling users to obtain spatial cues without interfering with their awareness of background noise. By highlighting the innate processes that enable environmental learning without visual input, this study substantially advances our knowledge of how blind people use sensory integration to navigate their surroundings. It emphasizes the superiority of multisensory cues in enhancing spatial perception and cognitive processing during navigation tasks by comparing the effects of unisensory and multisensory feedback. The results also demonstrate the beneficial effects of white noise on memory, attention, and recall. However, the lack of effects from binaural audio feedback suggests that blind individuals employ alternative adaptive strategies. Furthermore, by developing a novel bus route detection algorithm and a portable, user-friendly tool that improves navigation by providing crucial spatial information beyond what a cane can offer, the research advances assistive technology for the blind and visually impaired people. With potential applications extending to different environments, public transportation, and smart city infrastructures, future advancements could include advanced AI for real-time processing and broader environmental interaction capabilities, creating more inclusive environments for people with visual impairments.