National Repository of Grey Literature 26 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
The relationship between substantia nigra echogenicity and speech and voice disorders
Adamkovičová, Lenka ; Novotný, Kryštof (referee) ; Mekyska, Jiří (advisor)
Transcranial sonography is a quick, simple and noninvasive examination method that allows to capture the loss of Substantia nigra in the brain. This loss is associated with the development of Lewy body disorders, and a confirmed correlation between Substantia nigra loss and development of dementia with Lewy bodies would allow for more accurate diagnosis of the disease. This thesis aims to investigate the accuracy of automated classification of individuals using a machine learning model, both according to their diagnosis of early DLB and also according to the size of Substantia nigra loss based on TCS examination. Automated acoustic analysis was applied to calculate speech and language parameters, those were statistically processed and then used to train a machine learning model. In a comparison of two binary classification problems it was found, that the model stratified by the size of Substantia nigra loss achieved lower accuracy than the model stratified by a diagnosis to healthy controls and persons with early-stage dementia with Lewy bodies. In addition, no correlation between SN hyperechogenicity and severity of DLB was confirmed.
Monitoring of long-term effects of repetitive transcranial magnetic stimulation on speech and voice in patients with Parkinson's disease
Kaplan, Václav ; Novotný, Kryštof (referee) ; Mekyska, Jiří (advisor)
An individual's response to dopaminergic therapy for Parkinson's Disease (PD), which often presents with hypokinetic dysarthria, varies in its effect on speech disorders. This study examines the long-term effects of alternative treatment using repetitive transcranial magnetic stimulation (rTMS) in PD patients. The aim is to conduct research into acoustic and statistical analyses employed in similar studies in the past, quantify treatment-induced changes using a set of parameters, and statistically evaluate the outcomes. Acoustic parameters describing phonation, articulation, and prosody (areas of speech production) are selected. A database of recordings from patients with mild PD is utilized, from which 18 patients are chosen, participating in one pre-treatment measurement and four post-treatment measurements. Patients are divided into active and sham (placebo) groups. Observable changes in several parameters, particularly in phonation, are noted after rTMS treatment. However, the statistical analysis of acoustic parameters also highlights a significant placebo effect, as good, and often comparable results are observed in the sham group as well.
Assessment of Parkinson’s Disease Based on Acoustic Analysis of Hypokinetic Dysarthria
Galáž, Zoltán ; Brezany, Peter (referee) ; Sklenář, Jaroslav (referee) ; Mekyska, Jiří (advisor)
Hypokinetická dysartrie (HD) je častým symptomem vyskytujícím se až u 90% pacientů trpících idiopatickou Parkinsonovou nemocí (PN), která výrazně přispívá k nepřirozenosti a nesrozumitelnosti řeči těchto pacientů. Hlavním cílem této disertační práce je prozkoumat možnosti použití kvantitativní paraklinické analýzy HD, s použitím parametrizace řeči, statistického zpracování a strojového učení, za účelem diagnózy a objektivního hodnocení PN. Tato práce dokazuje, že počítačová akustická analýza je schopná dostatečně popsat HD, speciálně tzv. dysprozodii, která se projevuje nedokonalou intonací a nepřirozeným tempem řeči. Navíc také dokazuje, že použití klinicky interpretovatelných akustických parametrů kvantifikujících různé aspekty HD, jako jsou fonace, artikulace a prozodie, může být použito k objektivnímu posouzení závažnosti motorických a nemotorických symptomů vyskytujících se u pacientů s PN. Dále tato práce prezentuje výzkum společných patofyziologických mechanizmů stojících za HD a zárazy v chůzi při PN. Nakonec tato práce dokazuje, že akustická analýza HD může být použita pro odhad progrese zárazů v chůzi v horizontu dvou let.
Simulation of Noise Emitted by a Single-stage Gearbox
Motl, Daniel ; Hadaš, Zdeněk (referee) ; Lošák, Petr (advisor)
The level of noise and vibration of gearboxes is one of the most important parameters for today´s customers. This thesis deals with mathematical acoustic behavior modelling and its contribution to the gearbox design using finite element method. The process is presented at three computations models. Two of those were validated with experimental measurement. Acoustic analysis were performed with software FFT ACTRAN.
Optimisation of electric vehicles gearbox housing with focus on emitted noise
Fürich, Adam ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This thesis deals with the vibration and noise of the gearbox for an electric vehicle. The gearbox itself acts as an emitter of unwanted noise caused by vibration excitation of the internal components of the gearbox. It is therefore necessary to deal with a complex unit such as the gearbox at system level as soon as it is being designed. This can be achieved using analytical tools and software. In this thesis, in order to evaluate the validity of the designed gearbox, a procedure is developed using both technical experiment and numerical simulations. The effect of the bolt preload is not overlooked for the following computational modelling dealing with the radiated noise of the gearbox. The results obtained from the performed technical experiments were then evaluated and compared with the results of the computational models. In this way, it is possible to compare the different approaches, their limitations and weaknesses. Furthermore, the thesis deals with design modifications that are analyzed using computational modeling. The thesis is concluded with a brief description of the application of each approach and an evaluation of the gearbox design modifications.
Differential analysis of multilingual corpus in patients with neurodegenerative diseases
Kováč, Daniel ; Zvončák, Vojtěch (referee) ; Mekyska, Jiří (advisor)
This diploma thesis focuses on the automated diagnosis of hypokinetic dysarthria in the multilingual speech corpus, which is a motor speech disorder that occurs in patients with neurodegenerative diseases such as Parkinson’s disease. The automatic speech recognition approach to diagnosis is based on the acoustic analysis of speech and subsequent use of mathematical models. The popularity of this method is on the rise due to its objectivity and the possibility of working simultaneously on different languages. The aim of this work is to find out which acoustic parameters have high discriminative power and are universal for multiple languages. To achieve this, a statistical analysis of parameterized speech tasks and subsequent modelling by machine learning methods was used. The analyses were performed for Czech, American English, Hungarian and all languages together. It was found that only some parameters enable the diagnosis of the hypokinetic disorder and are, at the same time, universal for multiple languages. The relF2SD parameter shows the best results, followed by the NST parameter. When classifying speakers of all the languages together, the model achieves accuracy of 59 % and sensitivity of 72 %.
Computational modeling of gearbox housing acoustics
Horváthová, Dominika ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This master´s thesis deals with the acoustic emission of the gearbox housing. It contains a description of the procedure of solving individual numerical approaches and their results. Finally, it compares the influence of design modifications on acoustic emission.
Assessing movement of articulatory organs based on acoustic analysis of speech
Novotný, Kryštof ; Galáž, Zoltán (referee) ; Mekyska, Jiří (advisor)
Hypokinetic dysarthria is a motor speech disorder often present during Parkinson’s disease. It affects the speech system, including articulatory abilities. There are several speech parameters describing this domain, so it is suggested to deal with their mutual comparison. This work aims to design and describe an algorithm for calculating the parameters of articulation, adapted for the Czech language, and then compare their discriminative power. The acoustic analysis of speech included in it is done via the Praat program and basic machine learning algorithms such as Expectation-Maximization, Kmeans and linear regression are used for the subsequent data processing. The Mann-Whitney U test and representatives of linear, nonlinear and ensemble machine learning models using cross-validation and balanced accuracy are used for evaluation. The results are scripts for automatic assessment of vowel space area, for calculating articulation parameters and for their evaluation. The outputs of the analysis of two different databases (PARCZ and CoBeN) prove that differences in articulation can indeed be observed between normal and dysarthric speech. Based on the mutual comparison of results, it is therefore proposed in the work which parameters and models of machine learning are being appropriate for further dealing with this issue.
Application for dysarthria examination using test 3F for Android
Sarker, Joy Tomáš ; Mekyska, Jiří (referee) ; Mucha, Ján (advisor)
This bachelor thesis focuses on diagnosing dysarthria thru a diagnosis apparatus called “Test 3F dysarthria profile“. During an examination with the apparatus the examined person undergoes 45 exercises that are meant to test respiration, phonation, phonetics, and the volubility of certain speech organs. The examiner, a clinical speech therapist, assesses the execution quality of each exercise with a number from 0 to 2. On the grounds of received points from all the exercises the level of dysarthria is diagnosed. The 3F test in this bachelor thesis is implemented as an Android application for Android devices and is supplemented by a partial automation of the examination based on an acoustic analysis of recorded speech of the examinee. The recorded speech is pre-processed by segmentation into 25 ms long frames using Hamming window. From this aforementioned speech recording we can determine speech fundamental frequency, jitter, and shimmer. The main goal and outcome is the creation of a modern mobile application for Android devices which, with the help of the 3F test, will make diagnosing dysarthria easier.
Remote and passive speech monitoring application
Klimeš, Jiří ; Mikulec, Marek (referee) ; Kováč, Daniel (advisor)
Motor speech disorders in patients with Parkinson’s disease collectively referred to as hypokinetic dysarthria, occur in the early phase of the disease. Language plays an essential role in classifying speakers into healthy and those with dysarthria. Author explains which aspects of speech are most often affected. Then explains how mobile applications work on the Android operating system, and if it is possible to use them in passive and distant speech monitoring. Then the topic of voice call recording is described and how is it possible to implement this solution. Such application is then designed and partially developed.

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