Publication Date


Document Type


First Advisor

Rossing, Thomas D., 1929-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Physics


Shock (Mechanics)--Measurement; Piano


A pendulum was dropped on a piano key, throwing the piano hammer upwards to strike a stationary force transducer. Measurements of the hammer force pulse for different velocities show that the hammer behaves like a hardening spring, becoming stiffer as the impact velocity increases. The residual shock spectrum was obtained with an FFT analyzer. The maximum value of the shock spectrum, fmax, indicates the frequency at which the hammer is most effective at transferring its energy. As the hammer velocity increases, the shock spectrum broadens and fmax increases. Values of fmax, corresponding to velocities observed in a real piano, were obtained for three sets of hammers: properly voiced, hard, and soft, each set covering the range of the piano keyboard. The dependence of fmax on hammer velocity, stiffness, and position along the piano keyboard is shown to agree very well with the observed timbre of piano sounds for different dynamic levels, hammer stiffnesses, and keyboard position.


Includes bibliographical references (pages [78]-80)


ix, 80 pages




Northern Illinois University

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