Recent work and new axes of research for m o d a l y s, a sound synthesis program based on modal representation

Abstract

modalys, developed at Ircam after 10 years for research and musical applications, is based on modal representation of vibrating objects, mechanical or acoustical. Modal data (natural frequencies, damping factors, and deflection shapes) are obtained from: (1) analytic modeling for simple structures as ideal string, cylindrical or conical open/closed tubes, rectangular plate with a simply supported boundary condition or violin bridge, ...); (2) experimental measurements for real structures with complex shapes (violin body, soundboard of piano, flute,...); and (3) finally by numerical methods (finite-element methods) which allow the creation of any arbitrary virtual shapes. The vibrating object involved is generally a set of simple and linear substructures. Nonlinearities, when they exist, are introduced in the coupling of substructures, for example reed and tube for the clarinet. Dissipation plays a critical role in the perception of some vibrating musical objects. The type of damping used in our modal representation is referred to as proportional damping (dissipation phenomena are in this case constant or proportional to the square of frequency). However, this type of damping may not apply in any case to the real objects. In this presentation, some sound illustrations on recent results of research and application development with modalys will be presented and discussed.