Woodwind instrument simulation in real-time
Michael K. Park, Douglas H. Keefe · The Journal of the Acoustical Society of America · 1988
A real-time implementation of the McIntyre-Schumacher-Woodhouse time-domain description of musical oscillators (1983) has been developed using digital signal processing (DSP) hardware. The system is comprised of a microcomputer with installed DSP board including a digital-to-analog converter. The task is to perform a convolution and solve two simultaneous equations with nonlinearities for the unknown pressure and volume flow at successive instants of time. A table lookup with linear interpolation simplifies the original formulation. The reflection functions used in the convolution are calculated based upon analytical models of woodwinds, but the nonlinear valving mechanism is somewhat idealized. One can “play” the instrument via an MIDI keyboard controller. Each MIDI note-on message loads a different reflection function into the DSP board memory, while the pitch wheel controls “blowing pressure.” Recorded examples will be presented.