Psychoacoustical studies based on full physical modelling for acoustic guitars sound synthesis

Abstract

Manufacturers of musical instruments in large and small-scale face great difficulties in introducing new designs, materials and construction techniques mainly due to the considerable demand of raw materials, manpower and working time. In the case of stringed instruments, it is observed that the vast majority of the instruments manufactured nowadays are based on empirical reproduction of traditional models and that innovation processes, when they occur, are based mainly on trial and error methods. As decision support tools, virtual prototyping techniques combining physical modeling and computational simulation have proved useful because they allow, with a certain prediction level, the study of the effects of material properties and geometric parameters on the vibrational behavior of the instrument and on its sound produced.Thus, this project aims at contributing at development of a parametric tool to support the virtual prototyping process allowing the influence evaluation of materials and geometries on the sound produced by the instrument in the environment. In this context, the main objective of this project is to implement a fully-coupled physical model for guitar sound synthesis (abbreviated in Portuguese as MoFiCASSoVi). The synthesis process should provide the sound produced resulting from the interactions of the following subsystems: mechanisms associated with the musician's gesture, strings, instrument body and environment. Due to the complexity and diversity of the phenomena involved, the MoFiCASSoVi will be composed of models for each subsystem and will involve the use of different methods and softwares and, therefore, the instrument sound synthesis will result from a set of procedures. The second part of the project aims at including stochastic models to the sound synthesis process taking into account the uncertainties associated with the variability of the physical-mechanical parameters of the wood (density, damping and elasticities) and the geometric parameters of the instrument (dimensions and positioning of components). One of the objectives of this stage, therefore, is to quantify the impacts of these uncertainties on the vibratory behavior and on the guitar synthesized sound. Finally, psychoacoustic studies will be carried out in order to assess the influence of these impacts on the sound perception of individuals. Given the current pandemic resulting from the coronavirus and not knowing how long it will last, it is important to highlight the feasibility of carrying out the project under conditions of social isolation.