|
|
Computational modelling of voice propagation around the human head using finite element method
Ryšavý, Antonín ; Hájek, Petr (referee) ; Švancara, Pavel (advisor)
In the first part of this master's thesis there is briefly presented the biomechanics of the human voice creation and an overview of the hitherto published computational models of the vocal tract and dissemination of the acoustic waves around the human head. The second part of the thesis deals with the creation of the computational model of a dissemination of the acoustic waves through vocal tract and further into a space around the head during the pronouncing of the Czech vowel /a:/. The vocal tract is excited by a harmonic signal in the place of vocal chords. On the surface of the vocal tract and the part of the head including hair and skin there is defined an acoustic absorption. The dissemination of the acoustic waves in the vocal tract, in the near field around the mouth, in the area around the head and in the points on the cheeks is detailed mapped. The dissemination of the acoustic waves is analyzed in the points where the speech microphones are placed. Acoustic pressure dependence on frequency, transmission functions between defined points and the acoustic pressure amplitudes depending on the distance from the mouth are obtained. In particular, the frequency distortion of the spectra is observed at the points indicated. Furthermore, the radiation impedance in the mouth area is evaluated. The results obtained are compared with the results of the hitherto published experimental measurements and can be used for the exact measurement of human voice or for the frequency correction of the microphones during the scann of the speech and sing placced in the analyzed points.
|
|
|
The Analysis of impedance properties of the bridge in string instruments
Němec, Petr ; Nop, Patrik (referee) ; Jirásek, Ondřej (advisor)
It is a known fact that stringed instruments bridge makes an important part of "acoustic circuit" of their bodies. Bridge acts as an acoustic filter which has the biggest impact on 2 – 6 kHz band and high frequency bands. To find the connection between the impact of a specific acoustic and mechanical properties of a bridge and acoustical behavior of the entire instrument remains as a matter of further exploration. Aim of this thesis is to find the mentioned relations of a chosen materials in an accordance to their mechanical properties within a full range of materials with common bridge properties. The experiments are designed to determine mechanical and acoustic properties of chosen materials which are then used to fabricate bridges. Subsequently the acoustical behavior of instruments with chosen bridges is determined. Based upon these findings we propose specific solutions and suggest further research.
|
|
|
Parkinson disease diagnosis using speech signal analysis
Karásek, Michal ; Smékal, Zdeněk (referee) ; Mekyska, Jiří (advisor)
The thesis deals with the recognition of Parkinson's disease from the speech signal. The first part refers to the principles of speech signals and speech signals by patients suffering from Parkinson's disease. Further, it continues to describe the issues of speech signals processing, basic symptoms used for diagnosis of Parkinson's disease (e. g. VAI, VSA, FCR, VOT etc.) and reduction of these symptoms. The next part focuses on a block diagram of the program for the diagnosis of Parkinson's disease. The main objective of this thesis is comparison of two methods of feature selection (mRMR and SFFS). For classification have selected two different methods were used. The first method is classification kNN and second method of classification is Gaussian mixture model (GMM).
|
|
|
Analysis of Formant Areas During Sung Vowels
Kukosa, František ; Švancara, Pavel (referee) ; Jirásek, Ondřej (advisor)
The study analyzes the formant zones of male voices in singing vowels with main focus on opera, chest and head vocal registers. The results of this work are based on the recordings of five singers, taken in an anechoic chamber. For the analysis of these recordings in the frequency domain were used the FFT algorithm and the LPC analysis. The results describe the nature of the individual registers and show the importance of the singing formants for singers. Especially for opera vocal register where the vocal formants, along with a natural vibrato technique, are very important.
|
|
|
Stress recognition from speech signal
Staněk, Miroslav ; Přibil, Jiří (referee) ; Tučková,, Jana (referee) ; Sigmund, Milan (advisor)
Předložená disertační práce se zabývá vývojem algoritmů pro detekci stresu z řečového signálu. Inovativnost této práce se vyznačuje dvěma typy analýzy řečového signálu, a to za použití samohláskových polygonů a analýzy hlasivkových pulsů. Obě tyto základní analýzy mohou sloužit k detekci stresu v řečovém signálu, což bylo dokázáno sérií provedených experimentů. Nejlepších výsledků bylo dosaženo pomocí tzv. Closing-To-Opening phase ratio příznaku v Top-To-Bottom kritériu v kombinaci s vhodným klasifikátorem. Detekce stresu založená na této analýze může být definována jako jazykově i fonémově nezávislá, což bylo rovněž dokázáno získanými výsledky, které dosahují v některých případech až 95% úspěšnosti. Všechny experimenty byly provedeny na vytvořené české databázi obsahující reálný stres, a některé experimenty byly také provedeny pro anglickou stresovou databázi SUSAS.
|
|
|
Estimation of formant frequencies using machine learning
Káčerová, Erika ; Galáž, Zoltán (referee) ; Mekyska, Jiří (advisor)
This Master's thesis deals with the issue of formant extraction. A system of scripts in Matlab interface is created to generate values of the first three formant frequencies from speech recordings with the use of Praat and Snack(WaveSurfer). Mel Frequency Cepstral Coefficients and Linear Predictive Coefficients are extracted from the audio files in order to be added to the database. This database is then used to train a neural network. Finally, the designed neural network is tested.
|
|
|
Finite element modelling of voice propagation through the vocal tract and around the human head
Tomeček, Vojtěch ; Pellant, Karel (referee) ; Švancara, Pavel (advisor)
This diploma thesis deals with creating of finite element model for the analysis of acustic waves radiation through human vocal tract and through the head surrounding space. The thesis contains a short overview of the anatomy of relevant parts and a short overview of formerly published models relevant to the topic. Then the process of creating the 3D model of human head, including the vocal tract, based on CT scans, and the mesh itself follows. This is succeeded by the computational solution taking in the acount the acoustic absorption of the vocal tract walls and radiation into the open space. The results gained are compared to relevant literature on this topic. The changes in frequency spectra in specific nodes of the mesh are reviewed and compared to relevant literature on the topic. The results could be used as basis of eventual frequention corrections of microphones used for voice diagnosis or registration in general, eg of speach or singing.
|
|
|
Diagnosing Parkinson's disease from analysis of speech recording
Vymlátil, Petr ; Trzos, Michal (referee) ; Lněnička, Jakub (advisor)
This thesis is focused on diagnosing Parkinson’s disease from analysis of speech recording. Introduction of this work deals with description of voice production mechanism, it’s basic qualities and influence of hypokinetic dysarthria on speech. In next chapter, there is described voice signal and some methods of it’s preprocessing. Next part continues dealing with description of chosen individual symptoms, which are needed for PD diagnosing, followed by definition of chosen reduction methods and classifiers. There is a comparison of classify succes of naive bayes classifier, depending on chosen reduction method in last chapter of this work.
|
|
|
The Program simulating the mutes of brass instruments
Košař, Vojtěch ; Indrák, Michal (referee) ; Jirásek, Ondřej (advisor)
This Master’s thesis deals with the creation of a program that simulates an impact of sound mutes on the timbre of a trombone and a trumpet. The simulation in the Reaktor 6 environment is based on an analysis of this impact which compares the spectra and formant regions retrieved from the MATLAB environment. The analysis takes into account also the impact on harmonic overtones. Another part of this work is focusing on the theory of a trombone and a trumpet, their brief history, the parts they are consisting of and the principle of tone formation. In the Reaktor 6 environment there has been created also a sampler functioning as a virtual instrument for the trumpet and the trombon. The last part of the work deals with creating a simulation program with its structure and evaluation.
|
|
|
The Analysis of impedance properties of the bridge in string instruments
Němec, Petr ; Nop, Patrik (referee) ; Jirásek, Ondřej (advisor)
It is a known fact that stringed instruments bridge makes an important part of "acoustic circuit" of their bodies. Bridge acts as an acoustic filter which has the biggest impact on 2 – 6 kHz band and high frequency bands. To find the connection between the impact of a specific acoustic and mechanical properties of a bridge and acoustical behavior of the entire instrument remains as a matter of further exploration. Aim of this thesis is to find the mentioned relations of a chosen materials in an accordance to their mechanical properties within a full range of materials with common bridge properties. The experiments are designed to determine mechanical and acoustic properties of chosen materials which are then used to fabricate bridges. Subsequently the acoustical behavior of instruments with chosen bridges is determined. Based upon these findings we propose specific solutions and suggest further research.
|
guest ::
