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LPC Speech Coding
Zapletal, Ondřej ; Kyselý, František (referee) ; Rajmic, Pavel (advisor)
The contents of the thesis "LPC speech coding" are studies of this method of a parametric source coding, explanation of mathematical procedures that are used in it (linear prediction, autocorrelation, Levinson-Durbin algorithm, transfer to a form suitable for transmission, Chebyshev root searching polynomial method) and acquaintance with the signification and application of that method in real speech encoders. The task of the original project of this thesis is a description and simulation of a simple speech encoder based on LPC, which transforms a real speech signal into a bit flow, which contains all of the significant parameters for its backward reconstruction (LSF coefficients, pitch period, excitation level, voice detection - AMDF method). One part of this thesis is a discussion about currently used speech encoders.
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Assessment of speech signal quality
Tuleja, Peter ; Balík, Miroslav (referee) ; Míča, Ivan (advisor)
This paper discusses methods for evaluating the quality of the speech signal. Briefly describe the subjective methods for determining the quality of the speech signal. From subjective methods the pair-wise comparison and MOS score are presented. Objective intrusive methods are described in more detailed way - namely methods of the segmental SNR evaluated in time domain, method of the segmental SNR evaluated in the frequency domain and frame normalization method which uses LSE based estimator. At the end of this paper is described an experiment, in which the aforementioned methods are compared and than statistically evaluated.
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Proposal of Communication System in Company
Černá, Tereza ; Klech, Jan (referee) ; Zich, Robert (advisor)
Master´s thesis analyses modern methods of communication in company management. The objective is to discover out the crucial defects of this issue and to outline possible solutions which would improve the weaknesses – of internal communication. The master´s thesis consists of three parts: The theoretical part is concerned about communicational instruments which have been used by the operational company ČEPRO, a.s. The analytical part describes implementation of communicational instruments in the company. (external communication, internal communication, crisis communication and communication during the new product implementation) The proposal part recommends appropriate elements for efficient communication within the current communication system in the company.
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Identification of persons via voice imprint
Mekyska, Jiří ; Atassi, Hicham (referee) ; Smékal, Zdeněk (advisor)
This work deals with the text-dependent speaker recognition in systems, where just a few training samples exist. For the purpose of this recognition, the voice imprint based on different features (e.g. MFCC, PLP, ACW etc.) is proposed. At the beginning, there is described the way, how the speech signal is produced. Some speech characteristics important for speaker recognition are also mentioned. The next part of work deals with the speech signal analysis. There is mentioned the preprocessing and also the feature extraction methods. The following part describes the process of speaker recognition and mentions the evaluation of the used methods: speaker identification and verification. Last theoretically based part of work deals with the classifiers which are suitable for the text-dependent recognition. The classifiers based on fractional distances, dynamic time warping, dispersion matching and vector quantization are mentioned. This work continues by design and realization of system, which evaluates all described classifiers for voice imprint based on different features.
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Identification of significant spectral components in speach signal in stress
Dulesov, Egor ; Tučková, Jana (referee) ; Poměnková, Jitka (advisor)
The aim of this master’s thesis is to learn the problem of analysis and identification of significant spectral components in speech signal. Based on learning a special literature chooses the suitable methods of spectrum estimate. Does learning the literature in specification of testing of spectral components significate. Makes a procedure for identification of chosen speech formants. Does this procedure for audio signals both of in stress and in normal state. Estimates the results, compares efficiency of chosen methods and determine threshold for chosen formant of analyzed stress signal. States the recommendations for speech spectral analysis in stress situation.
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Speech segmentation into phonemes
Andrla, Petr ; Balík, Miroslav (referee) ; Sysel, Petr (advisor)
The programme for the segmentation of a speech into fonems was created as a part of the bachelor´s thesis. This programme was made in the programme Matlab and consists of several scripts. The programme serves for automatic and hand segmentation. Automatic segmentation is based on the method of following symptom. The audiorecords were elaborated by the programme and a operation of the automatic segmentation was analysed. A detailed manual was created to the programme too. Individual used methods of the elaboration of a speech were in the bachelor´s thesis briefly descripted, its implementations in the programme and reasons of set of its parameters.
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Automatic / Automated recogniton of emotional states based on utterance analysis
Pfeifer, Leon ; Atassi, Hicham (referee) ; Smékal, Zdeněk (advisor)
The diploma thesis deals with the analysis of human emotional states. The thesis consists of three parts. The first part is charcterize, the process of speech generating, from phonetic and psychological poin of view. In the second part there are proccesed metods and contextual things.(preprocessing of signal, voice activity detector). For calculation fundamental Frequency it was used metod of central clipping, another used metod is formant frequency analyse and the last is metod of determinatin of nuber of thorns and planes. In the thirt part there are proccesesed results of measurements performed by particural metods. It was scorred five different emotional states: neutral, anger, happiness, sadness and surprise. At the end of this part there are discussed results for each metod.
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Comparison of analysis of speech in dependence on age and gender
Báňa, Josef ; Smékal, Zdeněk (referee) ; Atassi, Hicham (advisor)
This thesis deals with analysis of speech signal in dependence on the gender and the age of the speaker. We tried to investigate through the features to find the best set for the automatic classification of speakers. It also contains a brief discussion about the speech signal and its characteristics. We used a program called Praat for the speech analysis purpose. This program is also described in this work. We mainly focused on the suprasegmental features of speech. Our first step was to make our own speech corpus which should contain speech records from speakers with various age and gender. We made the analysis using Praat and reported it within this thesis. For the automatic classification purpose, twelve features were selected basing on there quality criteria and used with a neural network to classify the speakers to classes with different age and gender. As it was mentioned, a neural network was used as a classifier. We used “Neural Network Toolbox” in the Matlab program to create and train our networks.
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Simple Dictation System
Hromádko, Michal ; Schwarz, Petr (referee) ; Szőke, Igor (advisor)
This master's thesis deals with design and developement of simple dictation system. It explains methods used for speech recognition and describes existing systems. Design of the system is focused primarily to create graphic user interface with large emphasis on user friendliness.
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