J. Rauhala and V. Välimäki, Parametric excitation model for waveguide piano

In this paper, a method providing an excitation signal for the waveguide piano synthesis is presented. The waveguide synthesis string model needs an excitation signal, which stimulates the model to resonate at the partial frequencies. This signal simulates the force pulse, which occurs in the piano when the hammer hits the string. In the proposed method, the excitation signal is produced by using additive synthesis with matching partial amplitudes and frequencies, and by adding bandlimited white noise into the signal. The excitation model takes into account the velocity at which the piano key is pressed, using bandstop and lowpass filtering. The proposed method is suitable for real-time piano synthesis, as it is controllable and computationally efficient.