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Artificial Vocal Folds for Source Voice Generation
Vašek, Martin ; Vampola, Tomáš (referee) ; Kamenický, Ján (referee) ; Mišun, Vojtěch (advisor)
The first part of this work focuses on ways to replace missing source voice in case of patients after total laryngectomy. The commonly used methods of voice rehabilitation are mentioned. Simple computational models are used to explore several principles of generating artificial source voice. Based on the knowledge of how a healthy human voice is generated, one of the ways to generate artificial source voice was chosen – a reed-based element in the configuration (-, +). The function of the reed-based element is based on a periodic bending of the reed and in the airflow cutoff created by this motion. The (-,+) configuration of the reed-based element causes a different behaviour, when compared to healthy vocal folds, important is, however, whether the generated acoustic signal has the right spectral characteristics, which enable the generation of voiced vowels of the human speech. Both experimental and computational models are used to study the behaviour of the reed-based element. The design of the experimental model is based on the preliminary experiments with simple reed-based elements, which were carried out at the beginning of my studies. The new experimental model is designed in such a way, that it enables changes to the reed geometry and its position towards the reed stop. The measurements carried out on the experimental model are mainly acoustical (measurements of the generated acoustical signal), but optical measurements of the reed´s movement and position are possible and used as well. Because of the nature of the reed-based element´s behavior, the fluid structure interaction must be taken into consideration in the computational model. A two-way model of fluid structure interaction is used between the fluid part of the computational model and the structural one. A partitioned solution is used to solve the fluid-structure interaction. The effect of specific input parameters on the function of both models (experimental and computational) is monitored. The influences of input parameters on the basic frequency of the generated signal (source voice), on the stability of the function and on other important characteristics are evaluated. The final chapters focus on the design of voice prosthesis in general. Some specific issues, which need to be solved when designing voice prosthesis, are highlighted.
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Artificial Vocal Folds for Source Voice Generation
Vašek, Martin ; Vampola, Tomáš (referee) ; Kamenický, Ján (referee) ; Mišun, Vojtěch (advisor)
The first part of this work focuses on ways to replace missing source voice in case of patients after total laryngectomy. The commonly used methods of voice rehabilitation are mentioned. Simple computational models are used to explore several principles of generating artificial source voice. Based on the knowledge of how a healthy human voice is generated, one of the ways to generate artificial source voice was chosen – a reed-based element in the configuration (-, +). The function of the reed-based element is based on a periodic bending of the reed and in the airflow cutoff created by this motion. The (-,+) configuration of the reed-based element causes a different behaviour, when compared to healthy vocal folds, important is, however, whether the generated acoustic signal has the right spectral characteristics, which enable the generation of voiced vowels of the human speech. Both experimental and computational models are used to study the behaviour of the reed-based element. The design of the experimental model is based on the preliminary experiments with simple reed-based elements, which were carried out at the beginning of my studies. The new experimental model is designed in such a way, that it enables changes to the reed geometry and its position towards the reed stop. The measurements carried out on the experimental model are mainly acoustical (measurements of the generated acoustical signal), but optical measurements of the reed´s movement and position are possible and used as well. Because of the nature of the reed-based element´s behavior, the fluid structure interaction must be taken into consideration in the computational model. A two-way model of fluid structure interaction is used between the fluid part of the computational model and the structural one. A partitioned solution is used to solve the fluid-structure interaction. The effect of specific input parameters on the function of both models (experimental and computational) is monitored. The influences of input parameters on the basic frequency of the generated signal (source voice), on the stability of the function and on other important characteristics are evaluated. The final chapters focus on the design of voice prosthesis in general. Some specific issues, which need to be solved when designing voice prosthesis, are highlighted.
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