Abstract

Parameter optimisation for woodwind single-reed models. (V. Chatziioannou, M. van Walstijn)
Vasileios Chatziioannou; Maarten van Walstijn

Time-domain modelling of single-reed woodwind instruments usually
involves a lumped model of the excitation mechanism. The parameters of
this lumped model have to be estimated for use in numerical simulations.
Several attempts have been made to estimate these parameters, including
observations of the mechanics of isolated reeds, measurements under
artificial or real playing conditions and estimations based on numerical
simulations.

In this study an optimisation routine is presented, that can estimate
reed-model parameters, given the pressure and flow signals in the
mouthpiece. The method is validated, tested on a series of numerically
synthesised data. In order to incorporate the actions of the player in
the parameter estimation process, the optimisation routine has to be
applied to signals obtained under real playing conditions. The estimated
parameters can then be used to resynthesise the pressure and flow
signals in the mouthpiece. In the case of measured data, as opposed to
numerically synthesised data, special care needs to be taken while
modelling the bore of the instrument. In fact, a careful study of
various experimental datasets revealed that for resynthesis to work, the
bore termination impedance should be known very precisely from theory.
An example is given, where the above requirement is satisfied, and the
resynthesised signals closely match the original signals generated by
the player.