Factors contributing to the multiple rate of piano tone decay

Abstract

Causes for the decrease in rate of piano tone decay with time of tone duration were investigated, including the following: different rates for different vibration modes or groups of modes, nonlinear transformation of mechanical energy to acoustical energy, storage of mechanical energy for subsequent acoustical radiation, transfer of energy between string modes perpendicular and parallel to the bridge, interference among strings that are almost exactly in tune, and change in rate of energy transfer from the multiple-string source to the bridge during the transition from an initial in-phase condition to a later out-of-phase condition. The last two closely related factors were found to control the rate change in most cases.