Tests were developed and conducted to determine an individual's subjective response to hand-induced vibration. These tests included equal sensations, threshold and annoyance tests. From the results of these tests, it was possible to make statements with regard to the physiological mechanisms that were responsible for an individual's perception of both discrete frequency and broad band vibration that was directed into the hand. By using the results of this and past investigations, it was possible to discuss an individual's perception of hand-induced vibration relative to the nature of the energy transfer that occurred between a vibrating handle and the hand. This discussion raised some questions with regard to the reliability of previous techniques that have been used to establish hazardous hand vibration criteria.