Vibrotactile amplitude discrimination on the wrist of visually impaired people
Support for spatial orientation and mobility of the blind and partially sighted people is still a hot and unsolved topic. It is well known that in supporting devices non-acoustic communication is recommended due to the role of the sense of hearing in the spatial orientation of the visually impaired people. Knowledge about discriminative ability of touch is crucial when designing devices which use tactile interfaces. The paper presents results of psychophysical studies connected with vibration perception on the wrist of blind and partially sighted people. The presented research examined the ability to identify the changes of amplitude of vibration on the wrist. Research was carried out on students of Special Schools for the Blind and Partially Sighted Children in Krakow. Thirty blind, partially and normal sighted people were examined. Transformed up/down method was used to determine vibrotactile amplitude discrimination threshold. Thresholds were obtained on the ventral wrist at 5 frequencies: 25, 32, 63, 125 and 250 Hz. Results were examined to find factors which could influence the threshold value.
Bibliogr. 10 poz., 1 il., 1 rys., wykr.
- 1. T. Majewski, Methodological guide for teachers working with children with vision impairment in the integration system, Warsaw, PWZN, 1997.
- 2. J. Wiciak, B. Borkowski, D. Czopek, A System for Determination of Areas Hazardous for Blind People Using Wave-vibration Markers Final Conclusions and Technical, Application Acta Physica Polonica A, 123.6 (2013) 1101 - 1105.
- 3. E. Bogusz, G. Mrozik, E. Skrodzka, Investigation of Vibratory Perceptron Thresholds in Blind and Visually Handicapped People in Chosen Areas of the Palm and the Wrist, Acta Physica Polonica A, 121(1A) (2012) A19 - A23.
- 4. J. Wiciak, B. Borkowski, D. Czopek, R. Trojanowski, A. Okarmus, L. Zalewska, E. Bogusz, A. Furman, E. Skrodzka, Blind in a big city: system for determination of hazardous and important areas for blind and visually impaired people using wavevibration markers, Kraków: AGH publishing houses, 2012.
- 5. D. Czopek, T. Korbiel, B. Kukulski, P. Małecki, P. Pawlik, B. Stępień, T. Wszołek, W. Wszołek, New methods of signal processing in the selected vibroacoustics problems, Monographs of the Department of Process Automation of the AGH in Krakow 2016, ISBN: 978-83-64755-20-0.
- 6. E. Ozimek, Sound and its perception. Physical and psychoacoustic aspects, Warsaw-Poznan: PWN 2002.
- 7. H. Levitt, Transformed Up-Down Methods in Psychoacoustics, The Journal of the Acoustical Society of America, 49(2 (2)) (1970) 467 - 477.
- 8. F. A. Kingdom, N. Prins, Psychophysics. Practical Introduction, Academic Press, 2010.
- 9. M. Chruściel, LabVIEW in practice, Legionowo: BTC Publishing House, 2008.
- 10. S. McClave, Probability and Statistics for Engineers, Boston: PWS-KENT Publishing Company 1986.