A Method for Modeling Finite Width Excitation in Physical Modeling Sound Synthesis of Bowed Strings

Abstract

In this article, a new method for modeling the excitation of bowed string instruments in digital physical modeling sound synthesis is presented. The method, referred to as fractional variable excitation point (FVEP) model, is based on physical modeling by digital waveguides (DWG). The FVEP model applies the fractional delay (FD) technique to the excitation of a finite width region of the bowed string. The method is applied to a physical model of the violin, but is extensible to all bowed strings. The FVEP model is applicable to DWG embracing several physical modeling variables, such as torsional vibrations and stiffness of the string. The effect of the FVEP model parameter values and the control parameter values of the violin model on the sound quality is examined. These results are compared to laboratory measurements of real bowed strings as well as to results from physical modeling synthesis techniques. It is found that the FVEP method provides major improvements over previous sound synthesis models, in terms of both sound quality and computational efficiency. Furthermore, it provides a novel way for the imitation of realistic excitation in bowed instrument sound synthesis.