Simulation of the weakly nonlinear propagation in a straight pipe: application to a real-time brassy audio effect

Nonlinear propagation in acoustic pipes is responsible for the brightness of the brass sounds at fortissimo nuances. Using the formalism of Volterra series, an acoustic model of this phenomenon is solved as an input-output system. An identification of the Volterra kernels leads to a structure composed of linear filters, sums, and instantaneous products of signals. A digital simulation which guarantees no aliasing is derived, from which real-time versions have been implemented.