Abstract
Objective: Blindness deprives a person of a significant part of sensory
information resulting in limited perceptual abilities and decreased
quality of life. Although some aspects of visual information, like the
shape of an object, can be conveyed by other senses, there is no easy
way to perceive color without using sight. To address this issue, we
developed the Colorophone sensory substitution device.
Method: In a way analogous to pixels in visual displays, we introduced
auxels (auditory pixels) that can be used as basic building blocks of a
generic auditory display. The developed auxel-based system realizes
real-time, spatial, color-to-sound conversion. We created a dedicated
software suite that enables the independent introduction of various
system features to ensure effective training. Four blind participants
assessed the prototype’s usability. The evaluation methods included:
auditory color recognition, object identification, and virtual sound
source localization tasks, as well as two self-descriptive methods: the
System Usability Scale and the NASA Task Load Index.
Results: The developed wearable system generates spatially calibrated
colorful soundscapes. It enables auditory color recognition and object
identification significantly above chance. However, analyzing complex
natural scenes remains challenging. Users judged the system’s usability
from good to best imaginable. The identified usability issues are
discussed together with the proposed solutions.
Conclusion: The Colorophone device shows promise for the future
development of a useful visual rehabilitation device; however, further
work is needed to eliminate existing usability issues.
Significance: The presented work contributes to developing a universal,
affordable and user-friendly visual rehabilitation device.