The question of whether the structural resonances have an effect on the acoustic behaviour of a wind instrument remains a subject of debate. Studies referring to an important effect due to wall vibrations are rare. The work of Dalmont et al. in [1] is an exception. They observed spectacular phenomena in the oscillation regime of an organ tube. It is remarkable that the cross section of the tube is slightly distorted and it vibrates basically on its first ovalling mode. A vibroacoustic model [2] offers a physique interpretation of this phenomenon: when the tube cross section is perfectly circular, the acoustic modes are coupled with the structural modes having the same circumferential symmetry. However, coupling between modes of different circumferential orders occur when the shell has small defaults in symmetry. Thus, the distortion of the shell permits the coupling between two kinds of modes that were not coupled in the absence of defaults. The aim of this work is to evaluate the role of the wall vibration effect on the acoustic behaviour of a simplified wind instrument having a slightly distorted body. For this, a simplified model of clarinet-like instruments is used to simulate the self-sustained oscillations. The attack time and the spectral centroid are used in order to quantify the perceptual effects of simulated signal on the timbre. Results corresponding to instruments with different thickness and distortions are compared.
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