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Using reverberators to modify space acoustics
Pavlikovský, Vladislav ; Orlovský, Kristián (referee) ; Kurc, David (advisor)
This diploma thesis deals with adjusting the reverberation time of enclosed spaces. It is divided into two thematic areas. The first thematic area deals with active systems that adjust the reverberation time, with a stronger focus on usage of reverberators to simulate secondary spaces. The second thematic area is the implementation of reverberators and their fundamental building blocks in Matlab.
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Software for simulation of acoustic pressure distribution
Hampl, Filip ; Schimmel, Jiří (referee) ; Kurc, David (advisor)
This semestral thesis deals with the creation of software to simulate the distribution of sound pressure. Basic principles of sound propagation are explained which are necessary for an understanding of the issue. There is a description of the velocity potential and its application in creating simulations. Another issue is the introduction of wavefield synthesis, which is essentially a technology for simulation of primary sources with secondary sources. Advantages of wavefiled synthesis are discussed as well as disadvantageous aspects. The practical part of this work is creating a user interface in Matlab, which allows user to plot the distribution of sound pressure of one or interaction of more emitters. Another possible outcome is to display the directional characteristics of real resources. At the very end of the work the direction of further work is outlined.
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Simulation of Sound Field of Multiple Sound Sources
Kohoutek, Jan ; Kurc, David (referee) ; Schimmel, Jiří (advisor)
The main task of this bachelor thesis is description of interaction of sound waves in field. To understand the whole topic important physical laws related to sound waves propagation are defined. It also deals with frequency and directional response of ideal point source which compares with real measured responses of direct-radiating electrodynamic loudpeaker. Thesis are shown some examples of sound fields on which are specified their behavior. It also desribe main properties for right functionality of line-array source. In practical part are measured acoustic pressure values which lead to creating a interpolation map of sound pressure level. This obtained map was compared with theoretical acoustic field. Part of this bachelor thesis is program which enable to simulate acoustic field created under variable sound and environment properties.
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Design of Reverberator for Room Acoustics Simulation
Húserka, Jozef ; Orlovský, Kristián (referee) ; Kurc, David (advisor)
This thesis deals with artificial simulation of acoustic spaces by using reverberators. Output of this document consists of four reverberation algorithms and function that evaluates objective parameters of acoustic space from impulse responses. Reverberators and script were implemented using Matlab. Graphical user interface is used to present all of the algorithms for easier usability. First chapter deals with objective parameters of acoustic spaces and the ways they are computed from impulse response. Second chapter describes various structures which are used to build reverberators. Those structures are used in third chapter in implementations of reverberators. Third chapter also compares all implemented reverberators . In last chapter experiment was made. Impulse responses of three spaces were measured and subsequently aproximated by algorithms implemented in this thesis.
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Objective Criteria for Room Acoustics Assessment
Zwins, Jiří ; Kurc, David (referee) ; Schimmel, Jiří (advisor)
The aim of this thesis is to define basic concepts of acoustics, a closer acquaintance with the defined objective criteria for evaluation of acoustic spaces and practical processing algorithms in Matlab. The central part is presented technique of calculating the reverberation time by integrating the measured room impulse response and its graphical output. The reverberation time is just one of objective assessment criteria acoustic spaces. The calculation algorithm is based on the principle of a closed space Dirac excitation pulse and the subsequent decline in energy determination of the reverberation time of the acoustic pressure. The analysis of the data samples were used specified areas in VUT Brno.
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Research for enclosed spaces impulse response influence on the auditory perception
Kišac, Matej ; Kurc, David (referee) ; Orlovský, Kristián (advisor)
This thesis deals with the acoustics of enclosed spaces and psychoacoustics. The first part is based on theoretical information about main structure of room acoustics and we concentrate on impulse response of the room. Next part is directed to the description of connection between basic parameters and room impulse response and their properties. These properties may be evaluated by means of methods processed in the third portion. Then we briefly focus on the panning process. The following section offers the knowledge acquired in the simulations of selected parameters(spacious impression, clarity, intimacy). In conclusion, it contains a solution of algorithm to simplify the generation of impulse response and comparison of objective parameters of my algorithm and the image method.
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Software for Processing of Sound Level Meter Data
Kříž, Petr ; Schimmel, Jiří (referee) ; Kurc, David (advisor)
This thesis deals with the measurement and evaluation of noise. Thesis summarizes the basic concepts of acoustics and describes methods of measurement and evaluation of noise, focusing on measurement uncertainty. Part of this work is the implementation of software for processing of sound level meter data NTi XL2 in Matlab including practical examples of its use.
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Automated Processing of Acoustic Measurements
Kaláb, Vojtěch ; Kurc, David (referee) ; Schimmel, Jiří (advisor)
The goal of the Semestral thesis is to develop and describe application for automatized processing of the outputs from sound level meter NTi XL2. Application is developed in Integrated Development Enviroment Visual Basic for Application and realized in Microsoft Excel. It evaluates various types of outputs, processes its results and display the measurement protocol, including graphs of selected variables and measurement uncertainty. Theoretical part is focused on electroacustics required for understanding and processing measurement.
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Noise Source Identification Using Beamforming
Kurc, David ; Míča, Ivan (referee) ; Schimmel, Jiří (advisor)
This master's thesis is focused on the noise source identification using microphone arrays and beamforming as the signal processing method. It describes parts of such a system and provides a comparison with other systems that serve a similar purpose (eg. NAH). Various types of microphone arrays are mentioned with their influence on the resulting ability to identify the noise source. We are further focusing on Delay-And-Sum technology, on which we are explaining the basic principles and constraints of beamforming. The practical part describes the implementation of the DAS method in MATLAB and C language, the specific structures of built microphone arrays and assembly of complete systems capable of identifying sources of noise. These systems were tested by performing a practical experiment. Achievements in the form of distribution maps of acoustic energy in the focused space are interpreted in the last chapter.
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Loudness Index Measuring
Hloušek, Pavel ; Mach, Václav (referee) ; Kurc, David (advisor)
This thesis deals with noise measuring. There are described methods of measurement and evaluation of noise, focusing on Steven’s loudness calculation method. Basic concepts of acoustics are provided in the first part. There are also mentions measurement of noise using microphones and sound level meter. The second part is focused on the practical solution of thesis. In which it is made measurement of noise using sound level meter NTi Acoustilizer and implementation of the graphical user interface for calculation of the Steven’s loudness index in Matlab.
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