The effect of wall vibrations on the air column inside trumpet bells

Vasileios Chatziioannou , Wilfried Kausel , Thomas Moore

The effect of wall vibrations on the sound of brass wind instruments is reported. There is experimental evidence showing that damping the vibrations of a trumpet bell alters the input impedance and transfer function of the instrument. Numerical simulations suggest that it is the axi-symmetric oscillations of the walls of the instrument that are responsible for the observed effects. Indeed, a finite element analysis of the effects of such oscillations on the air column yields results qualitatively similar to those of experiments. However, due to the complexity of the geometry and boundary conditions of a real instrument, the results of simulations do not agree quantitatively with the measured influence of the wall vibrations on the radiated sound from an actual trumpet. For this reason, straight trumpet bells have been manufactured that are expected to have boundary conditions more consistent with the assumptions of the numerical model. The results of both experimental measurements and numerical simulations of these custom-made bells are presented in this study.

Mots clés: brass; wall; vibrations; bell

Domaines: Acoustique [physics.class-ph]

Vasileios Chatziioannou, Wilfried Kausel, Thomas Moore. The effect of wall vibrations on the air column inside trumpet bells. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810995⟩