Understand and predict acoustic properties of heritage instruments: the case of a Besson trumpet of the Musée de la Musique of Paris

International audiencePlaying wind historical instruments is often conflicting with conservation and protection of museum collections. Some musical and acoustical properties of these instruments therefore remain unknown. Theoretical models can predict some of these properties from the only knowledge of the instruments geometry. A collaboration between Makutu Inria Bordeaux Sud Ouest team, Musée de la Musique - Philharmonie de Paris, Institut Technologique Européen des Métiers de la Musique (ITEMM) at Le Mans and the Centre de Recherche et de Restauration des Musées de France (C2RMF), lead to a procedure hereby applied to the museum collection Besson, which was a leading manufacture of wind instruments, and more specifically to several natural trumpets dating from the early 20th century. The geometry of the instruments has been measured non invasively by means of X-ray tomography in C2RMF. After extracting their bore (evolution of the inner diameter), their entry impedance has been computed. For one specific trumpet (E.0925), simulated data have been compared to measurements with excellent agreement. Despite many uncertainties on the way these instruments were played, simulated sounds can be computed. An « acoustical facsimile » of E.0925 has been crafted from the X-ray and impedance data, and played by a professional natural trumpet player. This allows to compare simulated sounds with human played sounds