To address some of these challenges, researchers have explored using a combination of modalities including tactile, audio, olfactory and cross-modality to build accessible maps and models for blind and low-vision learners.
Use of 3D representations:
Research shows that converting 2D tactile graphics to 3D models is beneficial in tactile visualization, especially for blind and low-vision individuals. Converting 2D to 3D allows for the following advantages:
- Direct representation of three-dimensional object.
- Comparison of different objects in relation to each other.
- Easy and accurate representation of shapes and sizes.
Pre-existing and handmade 3D models are sometimes used to show inherent three-dimensional information. These methods are much less common because they are time-consuming and have a high cost of production. With the invention of 3D printers, the cost of 3D models is in line with tactile graphics. 3D printing enables the production of custom and complex functional shapes using less material than traditional manufacturing methods.
a: Perkins Institution; 13-foot tactile globe structure built in 1837 (Image Source: Perkin's Institute for the Blind)
b: 3D relief globe at the Musée du Quai Branly (Image Source: Quai Branly Museum)
c: Perkins School for Blind tactile globe located at the Lighthouse, California (Image Source: LightHouse for the Blind and Visually Impaired)
d: Perkins Institution; metal casted world and city maps for blind learners (Image Source: Perkin's Institute for the Blind)
Adding interactive audio labels:
Literature shows that building on the strengths of audio labels, many researchers have investigated the addition of audio labels to tactile maps and models to replace braille and other visual labeling systems. When augmented with audio feedback, 3D maps and models have a wider effect on the accurate display of geographical information. Some of such advantages are as follows:
- Braille labels occupy space on maps and models.
- In order to fit braille in limited space, braille legends are used. But legends add cognitive load and shift of attention.
- Once braille is printed, it can only be reprinted in order to be updates. Unlike braille, audio labels can be updated and stored electronically.
- Many blind and low-vision learners are not braille literate.
Cross-sensory maps and models:
Cross-sensory design involves two or more different sensory modalities for information representation. Many researchers have developed cross-sensory learning aids which use audio-tactile to replace the visual modality for blind and low-vision users. For geographic information, the most common combination of perceptual modes literature supports is cross-sensory audio-tactile representation. This project primarily falls into the audio-tactile domain of cross-sensory learning tools.
