ASA 127th Meeting M.I.T. 1994 June 6-10

3pMU8. Synthesis of the sound pressure radiated by a guitar using a mixed time- and frequency-domain modeling technique.

Thomas Carter

Jean-Louis Guyader

Lab. Acoust. Vib., Batiment 303, Inst. Natl. des Sci. Appl., 69621 Villeurbanne, France

Antoine Chaigne

Telecom Paris, 75634 Paris Cedex 13, France

A general method has been previously developed by O. Beslin et al. [J. Acoust. Soc. Am. 89, 1868 (A) (1991)], using a variational method to describe the motion of a perforated plate, and a integral formulation for the modeling of the consecutive radiated sound pressure. This model is now adapted to the particular case of a guitar, whose top plate is represented by a rectangular orthotropic plate with hole and back cavity. The sound pressure computation is carried out in the frequency domain, for a point force acting at the bridge. This yields the pressure versus force transfer function H((omega)), from which the corresponding impulse response h(t) can be derived by means of inverse Fourier transforms. Finally, the guitar tones are obtained by convolving h(t) with a time-domain formulation of the force F(t) imparted to the bridge by a guitar string, using a finite difference method previously developed by A. Chaigne [J. Acoust. 5(2), 181--211 (1992)]. This model is used for investigating the influence of various plate parameters on timbre and sound quality of the instrument.