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Modelování vibračních vlastností lidských hlasivek
Vampola, T. ; Horáček, Jaromír ; Klepáček, I.
A 3D finite element model of the human larynx including the vocal folds was developed. The model enables to take into account phonation position (tinsion and adduction) of the vocal folds by positioning of the arythenoid and thyroid cartilages. Anisotropic properties of the three layers of the vocal fold living tissue (epitel, ligament and muscle) are modelled respecting the material nonlinearities with increasing prolongation of the tissue in longitudinal direction. The motion of the vocal folds is numerically simulated for a prescribed subglottal pressure loading the vocal folds by a periodic function in the time domain. the generated motion of the vocal folds seems to be qualitatively similar to a vibration mode known from clinical measurements.
Možnosti ladění a optimalizace akustických rezonančních vlastností vokálního traktu člověka
Radolf, Vojtěch ; Vampola, T.
The paper deals with optimization process finding such geometrical form of acoustical cavities of the human supraglottal spaces which leads to excitation of predefined acousic resonance, especially between a domain of the third and the fifth formant. The problem is solved by the transfer matrix method using conic acoustic elements for the vocal tract modelling and numerical method of searching a minimum of a goal function of several variables. The results should help to obtain a physical background for voice rehabilitation, for teaching of opera singers at musical facuoties and for better understanding of biomechanics of voice production.
Influence of velopharyngeal insufficiency on phonation of Czech vowels
Vampola, T. ; Horáček, Jaromír
The effects of velopharyngeal insufficiency on acoustic frequency-modal characteristics of human supraglottal spaces are investigated. The finite element model was developed from magnetic resonance images (MRI) of the subject during phonation. The influence of the velopharyngeal insufficiency on phonation of the Czech vowels /A,I,U/ is numerically simulated in time domain. The Liljecrants-Fantś pulse is used for excitation of the acoustic system.
1D model of the human vocal and nasal tract
Radolf, Vojtěch ; Vampola, T. ; Horáček, Jaromír
The paper deals with use of the transfer matrix method to determine acoustic characteristics of the human vocal tract connected with the nasal tract. The system models the influence of velopharyngeal insufficiency on production of Czech vowel /a/. The advantage of this method is significant shortening of the computing time compared to computations with 3D FE method. The model of the acoustical spaces is created by cylindrical elements. The calculation is carried out for periodic "L-F" signal applied at the position of glottis. Time dependent acoustic pressure and air flow volume velocity at the position of the lips and nose are computed. The resulting frequency response functions of the tract are compared with computations realized by 3D FE model.
Experimental investigation of acoustics of a simplified physical vocal tract model for phonation of vowel /A/ by LF pulse excitation
Kryštůfek, Jan ; Vampola, T. ; Horáček, Jaromír
The paper is focused on experiment of investigation of acoustics properties of 3D simplified model of human vocal tract for phonation of vowel /a/. The physical model was excited by LF pulse and acoustic pressure was measured in specific points. Measured values were evaluated and compared with values calculated by Finite Element Method (FEM).
Physical and mathematical modeling of effects of velopharyngeal insufficiency on acoustic characteristics of human vocal tract
Horáček, Jaromír ; Vampola, T. ; Veselý, Jan ; Růžička, P.
The effects of velopharyngeal insufficiency or clefting on acoustic frequency-modal characteristics of human supraglottal spaces are investigated for the Czech vowels /a/ and /u/. Finite element (FE) modelling is supported by experimental investigation using a physical model of the vocal and nasal tract fabricated by the rapid prototyping technique from the FE model.
Measurement and computation of acoustic characteristics of a simplified vocal tract model for phonation of vowel /a/
Kryštůfek, J. ; Vampola, T. ; Horáček, Jaromír ; Veselý, Jan
The paper is focused on experimental verification of 3D modeling of the acoustic characteristics of human vocal tract for phonation of vowel /a/ by the finite element method. The computational and experimental modal analyses were carried out on the mathematical and physical models of the vocal tract. The acoustic pressure computed by transient analysis in time domain is compared with measured resonant characteristics in frequency domain.
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.
Vliv geometrického tvaru hlasového ústrojí člověka na výslovnost českých hlásek
Vampola, T. ; Horáček, Jaromír
1D and 3D finite element models of supraglottal tract designed for Czech vowel /a/ are analyzed. Performed modal analysis is focused on formant frequencies. For tuning of the human vocal tract model according to measured acoustic pressure in front of the lips the multi objective optimization method is used.
Finite element model of male vocal tract considering clefting and interaction between hard palate and acoustic spaces
Dedouch, K. ; Horáček, Jaromír ; Vampola, T.
Results of a voice numerical simulation using finite element model of acoustic spaces corresponding to the human vocal tract for English vowel /a/ are presented. The approximate FE model was designed according to the data published in literature and amended by the model the nasal tract joint with the vocal tract by compliant bone of hard palate.

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15 Vampola, T.