Mat-1.3656 Seminar on
numerical analysis and computational science
Monday, March 3, 2014, room M233 at 14.15, Eirola & Stenberg
Tiina Murtola, Aalto", Department of Mathematics and Systems Analysis
Modelling vowel production
In this talk, a tunable vowel synthesis
model, which can be used as glottal pulse generator for more
sophisticated acoustic simulators of the vocal tract, is described
and tested. The core of the model consists of a low-order mass-spring
model of the vocal folds, Bernoulli flow with a viscous pressure loss
in the glottis, and a Webster resonator to represent the vocal tract.
With the aim of producing a minimal model, the impact of adding
dissipation along the vocal tract, a subglottal tract resonator, and
turbulence losses in the glottis, is investigated.
Tunability is achieved by optimising
four selected parameters in order to achieve target fundamental
frequency and phonation type. Solving the multi-objective
optimisation problem directly is not practical due to the complicated
dynamic behaviour of the model and long computing time of each
simulation. Instead, a three-step procedure combining constrained
single-objective optimisation, parameter space exploration, and
manual pulse shape selection is introduced and tested.