Graphical message transmission using the monotonic vibration function of a smart phone

Abstract

This study aimed at evaluating four vibrotactile capabilities for perceiving graphical information presented on a smart phone. Thirty-two blindfolded college students participated in four experiments to test their capabilities of two-point discrimination, relative and absolute judgments of line thickness, and recognition of basic shapes. All the information was received through the default vibration function of the phone, sensed by their scanning fingers. The results showed a good two-point discrimination accuracy rate, reaching 98.8% when the distance between two points was set at 3.2 mm; the relative judgment of line thickness reached the level of 78.3% accuracy when the two-line width difference ratio was set at 3%; the absolute judgment reached the level of 78.8% when the participants recognised line thickness from one of two. Overall, especially for the shapes judgment, the information transmitted by the various codes may be quite low. These findings should inspire advanced investigations and provide design guidelines.

Abstract

Practitioner Summary: This study tested four vibrotactile capabilities for perception of graphical information when solely using the monotonic vibration function of a smart phone. The results show low information transmission. These findings encourage advanced investigations of new coding systems so that relevant mobile applications could be developed to help the visually impaired.

Keywords:

• vibrotactile
• haptic interface
• visually impaired
• message transmission
• graphical information

Acknowledgements

We would like to acknowledge the previous work by C.-Y. Huang, Y.-W. Lee, Y.-H. Hsieh and R. F. Lin, and the work by Y.-Y. Wu, Z.-Y. Hong, J.-S. Zhan and R. F. Lin, which were presented in the 20th and 21st Annual Meeting of the Ergonomics Society of Taiwan, respectively. These works were preliminary studies of this research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We thank the grant support from the Taiwan Ministry of Science and Technology [grant number NSC101-2815-C-155-038-E], [grant number MOST103-2221-E-155-053-MY3] for funding the research and paper submission and thank Professor Yeong-Shu Chen for helping measure vibration information of the smart phone.