The Master's thesis deals with the creation of the numerical model that serves to analysis of the acoustic properties of separating construction of a wooden structure. The work includes theoretical basis for solving the subject, it discusses the airborne sound insulation of separating structures, focuses on wooden buildings, describes a computing environment ANSYS and model creation in it. More variants of model were compiled, CLT panel and frame construction. Model itself is using scripting language APDL and each step of creation is described. The results of numerical simulations describe the distribution of pressure in front and behind the separation construction. Results are compiled into graphs and single value of weighted airborne sound insulation is evaluated. In conclusion individual results of model variants are compared, model accuracy improvements are discussed.

The subject-matter of the diploma thesis is the research of effects of acoustic properties which are used for making piano bridges. In this work technological process of different piano bridges is discussed and problems related to it. In the next step materials like: maple, hardrock maple, laminated maple, laminated maple and mahagony, ebony, beech, laminated beech, crosswise glued beech, laminated beech and lignamon and hornbeam are compared in the aspect of acoustic properties. The differences among acoustic properties were searched by non-destructive methods with the help of device metering and final elements method. A frequence analysis of embedded grand piano soundboard was made. Statically eminent differences of acoustic properties were found among metering samples. There were found out the own frequences of metering soundboard and frequency spectrum in particular parts of piano bridge

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Acoustic pressure in environment protection programs of developed countries is the one of most important issue after air and water pollution. Acoustic pressure is all around us, such like machines, traffics and some other things. It is not possible to completely stop the noise, but there are some certain ways were used to reduce it up to acceptable limits. The aim of this work is to measure the acoustic noise and find solution to reduce it. The first measurements were done indoor (workplace studio) focused on room acoustic. We measured the acoustic pressure for three heights in different places,but finally the most important results were selected and compared with respect to each others. The next measurements were performed outdoor to collect the results about spread of the noise, which were analyzed with certain limits. The main goal was to find how to safe the human health and maintain peaceful and healthy environmental.

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This thesis deals with the theoretical and practical part of the phenomenon of acoustic emission. The thesis examined the theoretical foundations of this phenomenon and also described the equipment that was used in the laboratory of VUT in Brno to perform measurements. Then measurements and their analysis were described. Several possible errors that occurred during the work on the thesis were also described. Error description is the basis for error-free laboratory testing and for improving the quality of laboratory testing.

Disscusion of influencis of shape and dimension of human ear-canal in gain characteristic inclucing pressure wave applied on tympanic membrane in earphone implementation.

This theses is focused on possibilities of sorption properties decrease of musical instruments soundboards. This task should be solved with respect to sustainability of previous acoustics properties or their improving. The resonance wood specimens has been fabricated and conditioned to the relative humidity of 40 % The specimens were divided into three groups. The first one with natural properties, the second one treated by the temperature of 180 °C and the last one was treated by 200 °C. Specimens were conditioned all together to the relative humidity of 60 % and at the last step at 80 %. The conditioning was isothermal with the temperature of 20 °C. Swelling and hygroscopicity establishment was based on dimensions and weight measurement during conditioning of specimens. The first, second and longitudinal natural oscillation frequency of the specimens were determined by free-free resonant frequency method. Longitudinal and transversal sound propagation velocity were measured using Fakopp Ultrasonic Timer. Dynamic Young’s modulus (E´L,E´RT), dynamic bend Young’s modulus (Eb), acoustic constant (KL, KRT), characteristic impedance (ZL, ZRT), acoustic conversion efficiency (ACEL, ACERT), relative acoustic conversion efficiency (RACEL, RACERT) and damping coefficient (tan δ) were determined using the measured data. The treatment by 180 °C caused the decrease of volume swelling, which was 7,4% lower after the treatment. The hygroscopicity decreased by 2,8%. The treatment by 200 °C decreased swelling by 8,5% and the hygroscopicity by 4,3%. The different results of both treatments were observed in case of longitudinal sound velocity. In case of 180°C treatment the value of longitudinal sound velocity decreased by 1,6 %, whereas after treatment by 200 °C the increase by 2,1% was found. Acoustical properties E´, Eb, K, Z, ACE, RACE were decreasing due to the higher moisture content and tan δ was increased. Heat treatment by 180 °C has not significantly affected acoustical properties and sound velocity but the treatment by 200 °C caused their increase.

This diploma thesis primarily focuses on thermal modification of wood with superheated steam and its effect on elasticity and strength. The sample tested was 200 pcs of bending samples and 200 pcs compressive samples of European beech. These samples were divided into ten groups. One group was referential and the remaining nine groups were modified using different temperatures and during different time intervals. The main goal was to determine density, modulus of elasticity and rupture and to discover their dependence on the chosen mode of modification. The next part contains the analysis of the effect of thermal modification with superheated steam on the acoustic properties and the colour of wood. In the last part, the mass loss and the change in equilibrium moisture content was analysed in relation to the modification mode.

This thesis documents the possibilities of elements application in interiors in order to improve the acoustic characteristics of the space and it analyses the acoustic issues in contemporary interior and factors that affect it. The aim is to compare the acoustic absorption of selected types of filling materials and upholstery composition used in its production. The thesis includes a description of sample preparation, a procedure of measurement in an impedance tube, results processing to determine the sound absorption of tested materials and a measurement of foam cells sizes using microscope and Visiocell program. Acquired values were compared with each other.