Effect of hardening piano hammer felt on piano sound

Abstract

To clarify the effect of hardening the hammer felt of a piano on its sound, experiments evaluating the sound quality of the piano were performed using a new piano hammer. The adjustment of a piano hammer is necessary to obtain the desired tone. The elasticity and hardness of the hammer are also recognized as indicators of the condition of the instrument. To maintain the condition of piano hammers, piano craftsmen make adjustments using various tools and chemicals while listening to the resulting change in the sound after each alteration. Hammer adjustment is often performed based on intuition and experience. In this study, the quantity of the hardening agent was gradually increased, and a sound quality experiment was performed using a new Renner hammer. A low frequency of 58.27 Hz (A#1) was selected as the piano note investigated in this study because it is more affected than other frequencies by the hardening of the hammer. The results of this study indicate that the optimal amount of hardening agent needed to achieve a desired tone and desired tone should be determined before the agent is applied to the hammer felt.