Piano bridge and soundboard motion

Abstract

The bridge of a piano is the place where two important components, the strings and the soundboard, meet and interact. The motion of the bridge is important for understanding soundboard vibrations and sound production. This motion is also central to the interaction between strings, and to coupling of the different modes of a single string. Recent experimental and theoretical studies of bridge and soundboard motion are described. While the dominant motion is, as one would expect, perpendicular to the plane of the soundboard, the experiments show that motion parallel to this plane is also quite significant. Quantitative results for the in-plane motion are presented, and its role in sound production is discussed. We also consider the implications for modeling of soundboard and string motion. [Work supported by the National Science Foundation through Grant PHY-9722031.]