Efficient synthesis of musical tones having nonlinear excitations

Abstract

An efficient digital waveguide synthesizer is disclosed for simulating the tones produced by a non-linearly excited vibrational element coupled to a resonator, such as in a piano. In a preferred embodiment, the synthesizer creates an excitation pulse from a table containing the impulse response of a piano soundboard and enclosure. Alternatively, this excitation pulse can be synthesized by filtering white noise. The excitation pulse is fed into a filter that simulates the collision of the piano hammer and string. Because the hammer-string interaction is nonlinear, the characteristics of this filter vary with the amplitude of the tone produced. The filtered excitation pulse is then fed into a filtered delay line loop which models the vibration of a piano string. Because the excitation pulse already contains the effects of the resonator, the tone produced by the delay line loop does not require additional filtering in order to model the resonator.