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Volumetric model of human vocal folds
Vampola, T. ; Horáček, Jaromír
The article describes the vollumetric 3D FE model of real human vocal folds in a defined phonation position. The model was developed from the CT images of the plaster casts obtained by a special procedure during experiments with the excised human larynges, when the phonatioon caused by the airflow was suddenly stopped without changing the position of the fixed larynx. The model is determined for studies of dynamical stresses in the vocal fold tissue during vocal folds collisions.
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Proudění kolem profilu v kanále s dynamickými účinky
Fürst, J. ; Honzátko, R. ; Horáček, Jaromír ; Kozel, K.
The work deals with a numerical solution of steady and unsteady 2D inviscid incompressible flow over the profile NACA 0012 in a channel. The flow is described by the system of Euler equations. Cell-centered finite-volume scheme at quadrilateral C-mesh is used. Steady state solutions and also unsteady flows caused by the prescribed oscillations of the profile were computed. The method of artificial compressibility and the time dependent method are used for computation of the steady state solution.
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Dynamic and stability properties of an aeroelastic model
Horáček, Jaromír ; Kozánek, Jan ; Veselý, Jan
Frequency modal and damping characteristics of an aeroelastic model designed for experiments in the wind tunnel are studied. Based on the experimental modal analysis the structural mass damping and stiffnes matrices of the model are determined by identification procedures. The stability boundaries, i.e. the critical flow velocity for the flutter instability of the model were measured in the wind tunnel.
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Relation between own voice perception and skull vibrations
Vokřál, J. ; Horáček, Jaromír ; Černý, L. ; Veselý, Jan
Human own voice is percepted differently by speaker via air and bone conduction. The main aim of previous studies was to find out transfer function between these two ways of listening. Psychoacoustics methods, which were used mostly, gave relatively high differences between different subjects. Simultaneous recording of subject voice and vibrations of skull was used in your study. Low-pass filter effects found in vibrational spectra correspond to the psychoacoustics studies. These findings could be helpful in studying of self-perception of voice colour, the investigation of signer voice, the remediation of articulation disorders.
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Numerical modelling of production of czech vowel /a/ based on FE model of vocal tract
Švancara, P. ; Horáček, Jaromír ; Pešek, Luděk
Finite element (FE) model of the human vocal tract foe Czech vowel /a/ created by magnetic resonance imaging (MR) technique is modified to obtain radiation boundary condition outside the lips and used for numerical simulations. First resonant characteristics of FE model are studied using transient analysis boy pulse excitation and modal analysis. Then the pronunciation of the Czech vowel /a/ is simulated in time domain. Calculated time and frequency responses are compared with experimental data.
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Bifurcation phenomena in vocal fold vibrations - experiments in vitro
Horáček, Jaromír ; Švec, J. ; Veselý, Jan
The study presents experimental investigations focused on monitoring of the non-linear vibration effects, especially bifurcation phenomena in the vibration of human vocal folds. The experiments were performed with excised human larynges excited by airflow. Sudden changes between different regimes of the vocal fold vibration were observed when smoothly changing the tension of the vocal folds. The study reveals further details on the nature of sudden changes between voice registers. The results also point out the possible relationship between regular (physiologic) and irregular (pathologic) vocal fold oscillations.
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