Parametric Trombone Synthesis by Coupling Dynamic Lip Valve and Instrument Models

In this work, a physics-based model of a trombone coupled to a lip reed is presented, with the parameter space explored for the purpose of real-time sound synthesis. A highly configurable dynamic lip valve model is reviewed and its parameters discussed within the context of a trombone model. The trombone model is represented as two separate parametric transfer functions, corresponding to tapping a waveguide model at both mouthpiece and bell positions, enabling coupling to the reed model as well as providing the instrument’s produced sound. The trombone model comprises a number of waveguide filter elements— propagation loss, reflection at the mouthpiece, and reflection and transmission at the bell—which may be obtained through theory and measurement. As oscillation of a lip reed is strongly coupled to the bore, and playability strongly dependent on the bore and bell resonances, it is expected that a change in the parameters of one will require adapting the other. Synthesis results, emphasizing both interactivity and high-quality sound production are shown for the trombone in both extended and retracted positions, with several example configurations of the lip reed.