École Nationale Supérieure de
Techniques Avancées

Abstract

A plate reverberation unit is an electromechanical device used in sound studios in order to add artificial reverberation to audio signals. This device uses the vibrations of a thin plate to simulate the reverberation effect. The present thesis aims to simulate by physical models a generic plate reverberation. Thus, the user can choose the parameters of the virtual device : geometrical (lengths and thickness) and material physical parameters of the plate, boundary conditions, locations of exciting and sensing elements, influence of the presence of a porous plate. In addition to the comprehension of the phenomena involved in these devices, this approach permits the sound synthesis of existing plate reverberation units as the EMT-140 or the EMT-240, but also of other units with other real or fictive parameters sets. The approach followed is divided in three main parts : modelling a generic plate reverberation, measuring a real EMT-140 unit and defining the numerical methods for the sound synthesis on the audible frequency range. The physical models are based on structural dynamics and vibroacoustics theories, taking into account the physics of the involved vibration damping mechanisms, which are of great influence on the reverberation effect perception. The experimental work has been done on an EMT-140 plate reverberation unit. It identifies the whole set of parameters of this real unit and gives information about the limits of validity of the models. Finally, the time-domain numerical simulations are based on the finite differences method.