Vibrotactile Perception: Differential Effects of Frequency, Amplitude, and Acceleration

High-frequency vibrations are an essential part of numerous manipulation tasks. A promising research area in particular are telemanipulation tasks where vibrations occurring in the remote environment are fed back through tactile displays. Two experiments concerning the perception of vibrations were conducted. The first experiment aims at determining whether vibrations are coded primarily by frequency, amplitude, or acceleration by human subjects. Results show that primarily frequency and amplitude, but not acceleration of the vibrations were perceived. In the second experiment, subjects´ just noticeable difference (JND) for frequency under different conditions was examined. The resulting JND of 18% for frequencies showed neither dependence on amplitude or acceleration, which were independently held constant, nor on the reference frequencies. Therefore, it is not necessary to adjust the subjective intensity for vibrations for each human operator when designing tactile displays