Vibrotactile performance by normal and hearing-impaired subjects using two commercially available vibrators.

The aim of this study was to measure vibrotactile sensitivity and stress pattern recognition of untrained normal-hearing and hearing-impaired subjects. Vibrotactile thresholds were measured as a function of frequency with two vibrators at three body placements. Stress pattern recognition was tested with two vibrators at two body placements. Vibrotactile threshold results indicate that wrist placements were less sensitive than fingertip placement and the hearing-impaired subjects were equally or less sensitive than the normal-hearing subjects. Vibrator plunger size had the greatest effect on threshold in the most sensitive frequency range of the skin. Stress pattern recognition results indicate that subject performance is a function of body placement but not a function of plunger size. Moreover, stress pattern recognition curves obtained in this study had lower plateaus for the hearing-impaired subjects than for the normal-hearing subjects. Implications for vibrotactile training are discussed.