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Analysis of impact of noise in recordings on the automated detection of hypokinetic dysarthria
Havelková, Nikola ; Galáž, Zoltán (referee) ; Kováč, Daniel (advisor)
This thesis deals with the automated detection of hypokinetic dysarthria by analysing the influence of noise present in recordings. Appropriate single-channel methods, specifically the spectral subtraction and Kalman filter, are selected and implemented in the MATLAB R2022a to enhance speech. These methods are also used for noise-free recordings, to which additive white noise was added. Afterwards, the effectiveness of these methods is objectively evaluated by using signal-to-noise ratio values. After enhancing of speech, interferences are extracted from the recordings. The effect of the presence of noise, as well as its subsequent suppression by individual methods, is then evaluated by statistical analysis, specifically using the Kruskal-Wallis test and the post hoc Dunn’s test. The probability of distributing parameters of clean, noisy and enhanced recordings, for which the effect of noise is significant, according to statistical tests, are plotted using violin and box graphs. Finally, the classification was done by logistic regression with the help of machine learning, where the effect of the presence of noise and subsequent speech enhancement on automated detection of hypokinetic dysarthria was described according to the area values under the ROC curve.
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Methods of acoustic signal sources impedance matching for their further processing
Havelková, Nikola ; Kubánek, David (referee) ; Koton, Jaroslav (advisor)
The purpose of this bachelor thesis is to get acquainted with the theoretical areas related to the issue of impedance matching using the so-called DI boxes. It is mainly the theory of balanced and unbalanced signal, parameters typical for DI boxes (THD, impedance, bandwidth, dynamic range, etc.), knowledge about the transformer, respectively about the coils, or last but not least the issue of operational amplifiers, which is for designing of active DI box absolutely essential. The specifications of the designed DI box based on this theory are subsequently determined and compared with commercially available models. The main target is to achieve better figures or at least get closer to them. Furthermore, the circuit diagram is designed and optimized to achieve predetermined parameters using simulation in the Multisim program from National Instruments. Regarding the resulting specifications of the DI box, a printed circuit board is designed to build a prototype of the device. After its completion, a test gauging using APx525 is done and the results are compared to the target figures.
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Methods of acoustic signal sources impedance matching for their further processing
Havelková, Nikola ; Kubánek, David (referee) ; Koton, Jaroslav (advisor)
The purpose of this bachelor thesis is to get acquainted with the theoretical areas related to the issue of impedance matching using the so-called DI boxes. It is mainly the theory of balanced and unbalanced signal, parameters typical for DI boxes (THD, impedance, bandwidth, dynamic range, etc.), knowledge about the transformer, respectively about the coils, or last but not least the issue of operational amplifiers, which is for designing of active DI box absolutely essential. The specifications of the designed DI box based on this theory are subsequently determined and compared with commercially available models. The main target is to achieve better figures or at least get closer to them. Furthermore, the circuit diagram is designed and optimized to achieve predetermined parameters using simulation in the Multisim program from National Instruments. Regarding the resulting specifications of the DI box, a printed circuit board is designed to build a prototype of the device. After its completion, a test gauging using APx525 is done and the results are compared to the target figures.
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Analysis of impact of noise in recordings on the automated detection of hypokinetic dysarthria
Havelková, Nikola ; Galáž, Zoltán (referee) ; Kováč, Daniel (advisor)
This thesis deals with the automated detection of hypokinetic dysarthria by analysing the influence of noise present in recordings. Appropriate single-channel methods, specifically the spectral subtraction and Kalman filter, are selected and implemented in the MATLAB R2022a to enhance speech. These methods are also used for noise-free recordings, to which additive white noise was added. Afterwards, the effectiveness of these methods is objectively evaluated by using signal-to-noise ratio values. After enhancing of speech, interferences are extracted from the recordings. The effect of the presence of noise, as well as its subsequent suppression by individual methods, is then evaluated by statistical analysis, specifically using the Kruskal-Wallis test and the post hoc Dunn’s test. The probability of distributing parameters of clean, noisy and enhanced recordings, for which the effect of noise is significant, according to statistical tests, are plotted using violin and box graphs. Finally, the classification was done by logistic regression with the help of machine learning, where the effect of the presence of noise and subsequent speech enhancement on automated detection of hypokinetic dysarthria was described according to the area values under the ROC curve.
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|
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Methods of acoustic signal sources impedance matching for their further processing
Havelková, Nikola ; Kubánek, David (referee) ; Koton, Jaroslav (advisor)
The purpose of this bachelor thesis is to get acquainted with the theoretical areas related to the issue of impedance matching using the so-called DI boxes. It is mainly the theory of balanced and unbalanced signal, parameters typical for DI boxes (THD, impedance, bandwidth, dynamic range, etc.), knowledge about the transformer, respectively about the coils, or last but not least the issue of operational amplifiers, which is for designing of active DI box absolutely essential. The specifications of the designed DI box based on this theory are subsequently determined and compared with commercially available models. The main target is to achieve better figures or at least get closer to them. Furthermore, the circuit diagram is designed and optimized to achieve predetermined parameters using simulation in the Multisim program from National Instruments. Regarding the resulting specifications of the DI box, a printed circuit board is designed to build a prototype of the device. After its completion, a test gauging using APx525 is done and the results are compared to the target figures.
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|
|
Methods of acoustic signal sources impedance matching for their further processing
Havelková, Nikola ; Kubánek, David (referee) ; Koton, Jaroslav (advisor)
The purpose of this bachelor thesis is to get acquainted with the theoretical areas related to the issue of impedance matching using the so-called DI boxes. It is mainly the theory of balanced and unbalanced signal, parameters typical for DI boxes (THD, impedance, bandwidth, dynamic range, etc.), knowledge about the transformer, respectively about the coils, or last but not least the issue of operational amplifiers, which is for designing of active DI box absolutely essential. The specifications of the designed DI box based on this theory are subsequently determined and compared with commercially available models. The main target is to achieve better figures or at least get closer to them. Furthermore, the circuit diagram is designed and optimized to achieve predetermined parameters using simulation in the Multisim program from National Instruments. Regarding the resulting specifications of the DI box, a printed circuit board is designed to build a prototype of the device. After its completion, a test gauging using APx525 is done and the results are compared to the target figures.
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