Vibrotactile performance of normal and hearing impaired subjects

Abstract

One-channel vibrotactile stimulation has been used in conjunction with auditory stimulation for acquisition of speech and language. Such dual-modality training will be the most advantageous when vibratory stimulation is optimized. The aim of this study was to measure sensitivity of untrained subjects exposed to vibrotactile stimulation. Vibrotactile thresholds and stress-pattern recognition curves were measured with two vibrators at three body placements. Five normal and seven hearing impaired subjects took part in the experiment. Two of seven hearing impaired subjects were unable to respond to applied vibrations. The results indicate that: (1) both wrist placements were less sensitive than fingertip placement; (2) vibrator plunger size had greatest effect in the most sensitive frequency range; (3) the hearing impaired subjects were equally or less sensitive than normal subjects; (4) stress-pattern recognition curves were a function of body placement but not a function of plunger size; and (5) stress-pattern recognition curves for hearing impaired subjects had lower plateaus than for normal hearing ones. Implications for vibrotactile training will be discussed. [Work supported by NIHR.]