Acoustical nonlinearities in the structural components of the piano
Lauren M. Neldner, Eric Rokni, Cierra Gibson, Thomas R. Moore · The Journal of the Acoustical Society of America · 2017
Anomalous frequency components in piano sound, commonly referred to as phantom partials, are generally believed to originate from a geometrical nonlinearity of the string. Recent evidence suggests that phantom partials may also be produced by nonlinearities in the non-string components of the piano such as the soundboard, case, bridge, and frame. We report experimental results indicating that in addition to phantom partials, these nonlinearities associated with the piano structure also generate harmonic frequency components, which may affect the perceived sound more significantly than the phantom partials. The possible origins of this nonlinearity will be discussed.