Evaluating vibrotactile recognition ability of geometric shapes by using a smartphone

Abstract

Attempting to let visually impaired people perceive images instantly taken by a smartphone, Peng (2010) developed a mobile application that outlines images and vibrates the smartphone as user’s finger was upon the outlined graphics. The intention is encouraging, but the extent to which people can recognize graphical information via the means is unclear. Hence, this study aimed at evaluating the vibrotactile recognition ability of geometric shapes. Six blindfolded college students participated in this study to discriminate geometric shapes displayed on a smartphone by touching its screen with their forefinger. The phone vibrated as long as the finger touched the graphics. Four shapes, three sizes, and three widths of shape edge were tested as independent variables. Correct rate of judgments and the response time were measured as dependent variables. The results showed that triangle shapes had the highest correct ratio (73.48%), whereas pentagon shapes had the lowest correct ratio (63.59%). Furthermore, the participants required the longest time to judge triangle shapes and the shortest time to judge shapes with width ratio set at 100%. The findings direct new coding methods for display geometric shapes and testing the vibrotactile recognition ability with visually impaired people.