Trombone synthesis by model and measurement

Abstract

A physics-based synthesis model of a tromboneis developed using filter elements that are both theoretically-based and estimated from measurement. The model consistsof two trombone instrument transfer functions: one at theposition of the mouthpiece enabling coupling to a lip-valvemodel and one at the outside of the bell for sound production.The focus of this work is on extending a previouslypresented measurement technique used to obtain acousticcharacterizations of waveguide elements for cylindrical andconical elements, with further development allowing for the estimationof the flared trombone bell reflection and transmissionfunctions for which no one-parameter traveling wavesolution exists. A one-dimensional bell model is developedproviding an approximate theoretical expectation to whichestimation results may be compared. Dynamic trombonemodel elements, such as those dependent on the bore length,are theoretically and parametrically modeled. As a result,the trombone model focuses on accuracy, interactivity, andefficiency, making it suitable for a number of real-time computermusic applications. © 2011 Tamara Smyth and Frederick S. Scott.