Fatigue of the vibratory sense.

Abstract

The palm of the hand was stimulated continuously for 3 min. with a vibrating rod 1 mm. in diam. at frequencies of 64, 256, 700 and 1024 cycles per sec. 3 intensities of stimulation were used: 10. 25 and 40 db above threshold. Results showed a loss of sensitivity of from 5 to 15 db immediately after cessation of stimulation, with a gradual return to normal in 91/2 min. The loss is greater the higher the frequency and the greater the intensity of stimulation. The loss is the same whether measured at a frequency equal to or higher than the fatiguing frequency, but it is less if measured at a lower frequency.