A scale for rate of tactual vibration.

Observers were asked to make estimates of the rate of mechanical vibrations presented to the finger as pulses ranging from 2 to about 300 pps. From the functions generated by this study, a set of ten values of mechanical vibration rate was selected. In a second experiment additional observers were asked to learn to identify these values of rate. Information analysis of the data showed that, when rate alone is varied, observers can identify between three and five items correctly; when rate and intensity are covaried redundantly, between five and eight items can be identified correctly. These results are viewed as supporting those from studies of the DL for rate, and as evidence for a limited but useful role of rate discrimination in tactile displays of acoustic signals.