SOUND PRODUCTION IN RECORDERLIKE INSTRUMENTS .2. A SIMULATION-MODEL

A simple one-dimensional representation of recorder like instruments, that can be used for sound synthesis by physical modeling of flutelike instruments, is presented. This model combines the effects on the sou nd production by the instrument of the jet oscillations, vortex sheddi ng at the edge of the labium, and turbulence in the mouth of the instr ument. The jet oscillation model used is a modification of the semi-em pirical model by Fletcher [J. Acoust. Sec. Am. 60, 926-936 (1976)]. Th e steady-state drive of the acoustical oscillations in the pipe by the jet motion is represented by a pressure jump in the mouth of the inst rument. Vortex shedding at the edge of the labium during steady-state operation is taken into account by the use of a free-jet model. The co mbined effects of this nonlinearity and the jet-drive model enable one to correctly predict the steady-state amplitude of the fundamental. T he turbulence noise source is represented by an additional pressure ju mp across the mouth of the instrument having an amplitude scaling with the square of the jet velocity. This simple model appears to correctl y predict the noise level and its spectrum, both with and without osci llations of the jet. The transient response of the model is triggered by the initial Volume injection into the mouth of the instrument and i s dependent on the steepness of the driving pressure rise. (C) 1997 Ac oustical Society of America.