Vibration disappearance threshold may be raised by measuring it.

The influence of duration and intensity of the initial level of vibration on vibration perception threshold was studied in 15 healthy young subjects (aged 27.9 +/- 7.6 years) with a Vibrameter (Somedic AB Sweden). The threshold for increasing vibration corresponded well to the normal values published by the manufacturer. The thresholds for decreasing vibration were measured with three different starting conditions: starting from a low level of vibration, a high level, and from a low level sustained for one minute. Higher intensity and longer duration of the initial vibration raised the disappearance threshold significantly. Vibration disappearance thresholds can be influenced by measuring them. As a result, the investigation of the vibration sense calls for strict control over intensity and duration of the stimuli.