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Forsman, Jimmy. "Game engine based auralization of airborne sound insulation." Thesis, Umeå universitet, Institutionen för fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149498.
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Describing planned acoustic design by single number ratings yields a weak link to the subjective event, especially when the single number ratings are interpreted by others than experienced acousticians. When developing infrastructure, tools for decision making needs to address visual and aural perception. Visual perception can be addressed using game engines and this has enabled the establishment of tools for visualizations of planned constructions in virtual reality. Audio engines accounting for sound propagation in the game engine environment are steadily developing and have recently been made available. The aim of this project is to simulate airborne sound insulation by extending the support of recently developed audio engines directed towards virtual reality applications. The case studied was airborne sound insulation between two adjacent rooms in a building, the sound transmitted to the receiving room through the building structure resulting from sound pressure exciting the structural elements in the adjacent source room into vibration. The receiving room composed modelled space in the game engine Unreal Engine and Steam Audio was the considered audio engine. Sound transmission was modelled by filtering based on calculations of transmission loss via direct and flanking paths using the model included in the standard EN 12354-1. It was verified that the filtering technique for modelling sound transmission reproduced attenuations in correspondence with the predicted transmission loss. Methodology was established to quantify the quality of the audio engine room acoustics simulations. A room acoustics simulation was evaluated by comparing the reverberation time derived from simulation with theoretical predictions and the simulated reverberation time showed fair agreement with Eyring’s formula above its frequency threshold. The quality of the simulation of airborne sound insulation was evaluated relating the sound field in simulation to insulation classification by the standardized level difference. The spectrum of the simulated standardized level difference was compared with the corresponding sound transmission calculation for a modelled scenario. The simulated data displayed noticeable deviations from the transmission calculation, caused by the audio engine room acoustics simulation. However, the simulated data exhibited cancellation of favourable and unfavourable deviations from the transmission calculation resulting in a mean difference across the spectrum below the just noticeable difference of about 1 dB. Single number ratings was compared and the simulated single number rating was within the standard deviation of how the transmission model calculates predictions for a corresponding practical scenario measured in situ. Thus, the simulated data shows potential and comparisons between simulated data, established room acoustics simulation software and in situ measurements should further be made to deduce whether the deviations entails defects in the airborne sound insulation prediction or is an error imposed by the audio engine room acoustics simulation.
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Massaglia, J. F. "Modelling the sound insulation of corrugated roof structures : an extended transfer matrix approach." Thesis, University of Salford, 2017. http://usir.salford.ac.uk/43778/.
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Over the course of this work, the transfer matrix method (TMM) was implemented and studied for its potential in predicting the sound insulation characteristics of corrugated dual leaf roof structures. A model of periodically connected plates, using Fourier expansions, was derived independently and extended in this work to include the stiffness of connectors and orthotropic plates, and intermediate beams in the framework of the structure. The same principles were applied in deriving the transmission loss through periodically stiffened plates, as a proxy for corrugated panels. At the same time, corrugated plates were modelled as equivalent orthotropic panels, a process which is compatible with the TMM without particular modifications. Infill materials were modelled using simple fluid representations and more complex poroelastic behaviour. The point-connected plate models were combined with the TMM to enable multiple layers of infill materials between the two plates, by using an effective fluid approach. The stiffness of typical roof connectors was obtained with numerical simulations, and used in predicting transmission loss. Corrections were introduced to simulate diffuse laboratory conditions and enable meaningful comparisons to available data. The limitations of a simple orthotropic plate model compared to laboratory measurements and the ribbed plate model were identified. A number of measurements of dual leaf partitions and full roof systems were compared to the TMM and point-connected plate models, finding typically good agreement at low to mid-frequency, and a strong dependence of high frequency transmission loss on connector stiffness.
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Тищенко, Олена Петрівна. "Акустичне облаштування домашнього кінотеатру." Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/42428.
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В роботі описується та аналізується інформація що до геометрії на плану приміщення домашнього кінотеатру, умов створення задовільного часу реверберації. Були проаналізовані дві концепції приміщень для домашнього кінотеатру. Заглушене приміщення являє собою приміщення з малим значенням часу реверберації, відповідно, більш детальним підбором звукопоглинаючих матеріалів та високим показником звукоізоляції. Приміщення з акустичним полем залу володіє більшим значенням часу реверберації, задовільним значенням сумарного рівню шуму порівняно з допустим рівнем сумарного шуму у суспільних закладах в нічний час та простим набором звукопоглинальних матеріалів.The work aims to calculate the acoustic design of a damped room and a room with an acoustic field of the hall, which intended for a home theatre. The paper describes and analyses information on the geometry of the layout of the home theatre room, the conditions for creating a satisfactory reverberation time. Two home theatre room concepts were analyzed. A damped room is a room with a short reverberation time, respectively, a more detailed selection of sound-absorbing materials, and a high rate of sound insulation. The room with the acoustic field of the hall has a high value of the reverberation time, a satisfactory value of the total noise level compared to the admissible level of total noise in public institutions at night, and a simple set of sound-absorbing materials.
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Berková, Petra. "Predikce zvukoizolačních vlastností dělicích stavebních konstrukcí a zabezpečení akustické pohody v interiéru budov." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-233798.
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This thesis deals with the properties of soundproof partition structures in the low-frequency sound at impact sound insulation and security of acoustic comfort inside buildings. The prediction of impact sound is a simulation laboratory measurements of impact sound. The work is based on the occurrence of frequent complaints of inhabitants of residential homes for subjectively poor impact sound insulation of horizontal dividing structures, whose top layer is formed laminate. Although these structures conform in terms of impact sound insulation in accordance with the requirements of CSN 73 0532: 2010, residents complain about the subjective perception of the sounds of lower frequencies. A noise with a distinctive character of sound at low frequencies has been proved by measuring the spectral analysis and evaluation of sound pressure levels caused by the movement of persons roof construction to the floor. On the measurement and evaluation carried out in accordance with the measurement and evaluation of noise in non-working environment can be related requirement under the Regulation No. 272/2011 Coll. "On the protection of health from the adverse effects of noise and vibration." Occupational noise limits for protected buildings interior space do not apply to noise from ordinary use of the apartment. Under current legislation, the problem is in the Czech Republic at present insoluble. Therefore, this work explores ways evaluation of impact sound and delivery is determined conclusions. With the low-frequency impact sound insulation is also related to the latter part of this dissertation, where the computing program ANSYS (version 14.0) is simulated laboratory measurements of impact sound insulation of the real structure. The paper presents the results of simulation, and the sound pressure level in the receiving room to třetinooktávového band 630 Hz. These results are compared with measured values modeled in the laboratory.
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Novotný, David. "Polyfunkční dům." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226610.
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The main concern of this thesis work is the five-storey multifunction building. The house will consist of 22 residential units and one barrier-free apartment to which they belong cellar and two establishments. The building will have four above ground and one underground floor.
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Kernen, Ulrica. "Airborne sound insulation of floating floors." Licentiate thesis, KTH, Byggnader och installationer, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1036.
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Cambridge, Jason Esan. "The Sound Insulation of Cavity Walls." Thesis, University of Canterbury. Mechanical Engineering, 2012. http://hdl.handle.net/10092/7332.
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Lightweight building materials are now commonly employed in many countries in preference to heavyweight materials. This has lead to extensive research into the sound transmission loss of double leaf wall systems. These studies have shown that the wall cavity and sound absorption material placed within the cavity play a crucial role in the sound transmission through these systems. However, the influence of the wall cavity on the sound transmission loss is not fully understood.
The purpose of this research is to obtain a comprehensive understanding of the role played by the wall cavity and any associated sound absorption material on the sound transmission loss through double leaf wall systems. The research was justified by the fact that some of the existing prediction models do not agree with some observed experimental trends.
Gösele’s theory is expanded and used in the creation of an infinite and finite vibrating strip model in order to acquire the desired understanding. The sound transmission loss, radiated sound pressure and directivity of double leaf systems composed of gypsum boards and glass have been calculated using the developed model. A method for calculating the forced radiation efficiency has also been proposed. Predictions are compared to well established theories and to reported experimental results.
This work also provides a physical explanation for the under-prediction of the sound transmission loss in London’s model; explains why Sharp’s model corresponds to Davy’s with a limiting angle of 61° and gives an explanation for Rindel’s directivity and sound transmission loss measurements through double glazed windows. The investigation also revealed that a wide variety of conclusions were obtained by different researchers concerning the role of the cavity and the properties of any associated sound absorption material on the sound transmission loss through double wall systems. Consequently recommendations about the ways in which sound transmission through cavity systems can be improved should always be qualified with regard to the specific frequency range of interest, type of sound absorption material, wall panel and stud characteristics.
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Maluski, Sophie. "Low frequencies sound insulation in dwellings." Thesis, Sheffield Hallam University, 1999. http://shura.shu.ac.uk/3136/.
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Low frequency noise transmission between dwellings is an increasing problem due to home entertainment systems with enhanced bass responses. The problem is exacerbated since there are not presently available methods of measurement, rating and prediction appropriate for low frequency sound in rooms. A review of the classical theory of sound insulation and room acoustics has shown that both theories are not applicable. In fact, the sound insulation of party walls at low frequencies is strongly dependent on the modal characteristics of the sound fields of the two separated rooms, and of the party wall. Therefore methods originally developed for measurement conditions where the sound field was considered diffuse, may not be appropriate for room configurations with volumes smaller than 50m3 and for frequencies where sound wavelengths are large. An alternative approach is proposed using a Finite Element Method (FEM) to study the sound transmission between rooms. Its reliability depends on the definition of the model, which requires validating measurement. FEM therefore does not replace field or laboratory measurements, but provides complementary parametric surveys not easily obtainable by measurements. The method involves modelling the acoustic field of the two rooms as an Acoustic Finite Element model and the displacement field of the party wall as a Structural Finite Element model. The number of elements for each model was selected by comparing the numerical eigenfrequencies with theoretical values within an acceptable processing time and error. The simulation of a single room and of two coupled rooms, defined by linking the acoustic model with the structural model, were validated by comparing the predicted frequency response with measured response of a 1:4 scale model. The effect of three types of party wall edge condition on sound insulation was investigated: simply supported, clamped, and a combination of clamped and simply supported. It is shown that the frequency trends still can be explained in terms of the classical mechanisms. A thin masonry wall is likely to be mass controlled above 50Hz. A thick wall is stiffness controlled, below 100Hz. A clamped thin wall provides a lower sound insulation than a simply supported, whereas a clamped masonry wall provides greater sound level difference at low frequencies than a simply supported. The sound insulation of masonry walls are shown to be strongly dependent on the acoustical modal characteristics of the connected rooms and of the structural modal characteristics of the party wall. The sound pressure level difference displays a sequence of alternating maxima and minima about a trend, dictated by the properties of the party wall. The sound insulation is lower in equal room than in unequal rooms, whatever the edge conditions and smaller wall areas provide higher sound insulation than large areas. A correction factor is proposed as a function of room configuration and wall area and edge conditions. Attempts to quantify the factor were made using statistical and deterministic analyse, but further work is required.
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Sullivan, Rory Daniel. "Sound insulation of brick diaphragm walls." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318231.
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Toyoda, Masahiro. "Sound insulation strategies for building constructions." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/143996.
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Kyoto University (京都大学)0048
新制・課程博士
博士(工学)
甲第12306号
工博第2635号
新制||工||1372(附属図書館)
24142
UT51-2006-J298
京都大学大学院工学研究科都市環境工学専攻
(主査)教授 髙橋 大弐, 教授 鉾井 修一, 助教授 伊勢 史郎
学位規則第4条第1項該当
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Mahmud, Md Amin. "Beam-tracing prediction of room-to-room sound transmission." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/64154.
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Modeling sound transmission is a challenging task. An existing beam-tracing model for empty, parallelepiped rooms with specularly-reflecting surfaces is extended to predict room-to-room sound transmission between a source and receiver rooms separated by a common wall. This wall is modeled as one locally-reacting homogenous partition with frequency-independent transmission loss. Besides, sound transmission is modeled in Ray-Tracing (CATT-TM) and FEM (COMSOL). A reference configuration consists of two identical reverberation rooms is chosen following the recommendations of the literature and most of the prescriptions of the reverberation room standard, ASTM 3423. The capability of various room-to-room predictions models, in particular, the phase and energy-based beam tracing models (PBTM, EBTM) in reproducing the results of the diffuse-field theory is investigated. Both EBTM and CATT-TM are found to be reasonably accurate in reproducing the diffuse sound field for a reverberation room (i.e. for diffuse sound fields). However, the predicted levels deviate considerably from the diffuse-field theory with changes in the acoustical characteristics of the room (room aspect ratio, the magnitude of the surface absorption and surface absorption distribution (i.e. for non-diffuse sound fields). EBTM has been validated in both source and receiver rooms through existing results from ODEON in the literature and by comparing the prediction results with the new CATT-TM for the reference configuration. PBTM has been compared with finite element method (COMSOL) results in the low-frequency region. Both phase-based models match well in source room with a reasonable discrepancy. However, the PBTM has not reproduced the sound field predicted by COMSOL in the receiver room. Moreover, Waterhouse effect is studied by both PBTM and EBTM model in the reverberation rooms which is ignored in the classical diffuse-field concept. However, its significant effect is exhibited near the reflecting boundaries inside the reverberation room only in the PBTM predictions. Hence, based on recommendations of the ASTM standards during measuring sound transmission between rooms, sources and receivers should be placed sufficiently far away from the reflecting surfaces, edges and corners of the rooms to avoid the errors due to the Waterhouse effect.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Öqvist, Rikard. "Variations in sound insulation in lightweight timber constructions." Licentiate thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26446.
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This licentiate thesis deals with the topic of variations and uncertainties in building acoustic parameters for lightweight timber constructions. A higher safety margin to the legal requirements is needed to compensate for acoustical uncertainties, which leads to higher costs. Building costs can be reduced if the variations can be identified and controlled. The project was limited to industrially prefabricated timber frame based volumes and massive timber based plate elements. This thesis is based on the work reported in three papers (A, B and C). In paper A, the variations in impact and airborne sound insulation were assessed and quantified in 30 nominally identical volume built apartments in a four-storey building. Large variations were found and the underlying causes were investigated. A statistically significant difference between floor numbers was found as the highest floor achieved better sound insulation. This difference was assumed to be caused by the higher static load on lower floors affecting the elastic layer used to structurally connect the apartments. In paper B, three room volumes were followed and measured at different stages of completion throughout the construction process. The objective was to test if acoustical deviations in the field can be identified at earlier construction stages. An ISO tapping machine was used to excite the floors and the response was measured at 20 positions. The airborne and impact sound insulation were measured in the finished building. Deviations were found, but these could not be traced to earlier stages of completion. In Paper C, the variations in sound insulation of a cross-laminated timber (CLT) building system was investigated. The construction was based on prefabricated wall and floor plate elements which were mounted at the building site. A number of acoustical uncertainties related to the measurement procedure were also investigated. The measurement uncertainty was small in comparison to the total variations. The degree of prefabrication for the CLT system was lower compared to the volume system, which indicated a greater scope for poor workmanship. All papers indicate a higher sound insulation on the upper floors in a building. It is therefore important to carefully design the elastic layer between floor numbers. The measurement uncertainty has been continuously considered in this thesis. In order to properly identify and quantify variations, the measurement uncertainty should be minimised. Advantages and drawbacks with different measurement methods and directions for future research are discussed in the concluding chapters.Godkänd; 2010; 20101110 (ricokv); LICENTIATSEMINARIUM Ämnesområde: Teknisk akustik/Engineering Acoustics Examinator: Professor Anders Ågren, Luleå tekniska universitet Diskutant: Teknologie doktor Christian Simmons, Simmons akustik & utveckling AB, Göteborg Tid: Torsdag den 16 december 2010 kl 13.00 Plats: F719 Taylor, Luleå tekniska universitet
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Buenafe, Mistén Louise. "Sound - Sense - Space: Might sound affect our experience of a room?" Thesis, Malmö högskola, Fakulteten för kultur och samhälle (KS), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-21463.
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Syfte: Rapportens syfte är att kartlägga om upplevelsen av ett rum kan förändras beroende på om och vilka ljud som spelas upp i rummet.Metod: I samband med en ljudinstallation på Plattan vid Malmö Högskola har rörelsemönster och beteende för Plattans besökare observerats. Dessutom har flera besökare besvarat en enkät.Resultat: Inga eventuella förändringar i rörelsemönstret eller beteendet för Plattans besökare kan ses som en konsekvens av ljudinstallationen. Det finns inte heller någon skillnad i enkätsvaren beroende på installationen. Slutsats: Resultatet ses som en konsekvens av bristfälliga forskningsmetoder. I rapportens slutsats bildas hypotesen att en installerad ljuddesign inte är en tillräcklig åtgärd i den undersökta typen av miljö. Tesen menar att en förändring av ljudmiljön och påverkan på människors upplevelse av rummet i första hand kräver akustiska åtgärder.
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Pánek, Martin. "Víceúčelový dům." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226543.
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The main concern of this thesis is to design a five-storey multifunctional house. The house is divided into the main living area to which it belongs especially residential units accessible by stairs from the ground floor and also basement boxes and room for prams. On the ground floor are also located the individual garage, store room and technology. The house has four floors and a basement, the basement are located mass garages. The house has a sloping wooden roof trusses.
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Olik, Marek. "Personal sound zone reproduction with room reflections." Thesis, University of Surrey, 2015. http://epubs.surrey.ac.uk/807178/.
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Loudspeaker-based sound systems, capable of a convincing reproduction of different audio streams to listeners in the same acoustic enclosure, are a convenient alternative to headphones. Such systems aim to generate "sound zones" in which target sound programmes are to be reproduced with minimum interference from any alternative programmes. This can be achieved with appropriate filtering of the source (loudspeaker) signals, so that the target sound's energy is directed to the chosen zone while being attenuated elsewhere. The existing methods are unable to produce the required sound energy ratio (acoustic contrast) between the zones with a small number of sources when strong room reflections are present. Optimization of parameters is therefore required for systems with practical limitations to improve their performance in reflective acoustic environments. One important parameter is positioning of sources with respect to the zones and room boundaries. The first contribution of this thesis is a comparison of the key sound zoning methods implemented on compact and distributed geometrical source arrangements. The study presents previously unpublished detailed evaluation and ranking of such arrangements for systems with a limited number of sources in a reflective acoustic environment similar to a domestic room. Motivated by the requirement to investigate the relationship between source positioning and performance in detail, the central contribution of this thesis is a study on optimizing source arrangements when strong individual room reflections occur. Small sound zone systems are studied analytically and numerically to reveal relationships between the geometry of source arrays and performance in terms of acoustic contrast and array effort (related to system efficiency). Three novel source position optimization techniques are proposed to increase the contrast, and geometrical means of reducing the effort are determined. Contrary to previously published case studies, this work presents a systematic examination of the key problem of first order reflections and proposes general optimization techniques, thus forming an important contribution. The remaining contribution considers evaluation and comparison of the proposed techniques with two alternative approaches to sound zone generation under reflective conditions: acoustic contrast control (ACC) combined with anechoic source optimization and sound power minimization (SPM). The study provides a ranking of the examined approaches which could serve as a guideline for method selection for rooms with strong individual reflections.
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Kernen, Ulrica. "Airborne sound insulation of single and double plate constructions." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-182.
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Trojáková, Michaela. "Penzion Pamferova Huť." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372261.
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This diploma thesis describes the design and processing of project documentation pension. The proposed facility is located in the village of Železná Ruda- Pamferova Hut. The site is widely used by tourists in winter and summer. This is partly basement building, which has 2 storeys and an attic. The roof is designed as a gabled dormer with a flat roof. The building is based on the footings of plain concrete and under the reinforced concrete pillars are designed shoe. Supporting, peripheral and partition walls are designed from sand-lime bricks SENDWIX. An exception is peripheral walls of the basement, which is in contact with soil, which is designed as a lost formwork. In the dining area, which has an open reinforced concrete columns. Ceiling structure will consist of prestressed ceiling panels SPIROLL. Perimeter walls are insulated using external thermal insulation composite system using insulation from stone wool. The building is functionally divided into three main parts with a common main entrance. The first part is a restaurant with a kitchen, storage and kitchen facilities. This section is designed restaurants with a total capacity of 26 persons, the capacity will be in the summer to expand the possible capacity of the terrace, which belongs to the dining room. It is also proposed sanitary facilities for visitors to the restaurant, kitchen with storage and facilities for staff. The second part is the wellness center, which consists of a gym and rooms with infrared sauna and whirlpool. This section is designed sanitary facilities for visitors separated for men and women. The last part of the pension, which used to accommodate 30 people and the background of the pension. Backgrounds pension means any technical equipment room, storage room for bikes and skis, and not least the individual room house, which also includes a room for personal hygiene. This thesis was created with an emphasis on a correct layout and architectural design, static requirements an
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Uhlíř, Karel. "Bytový dům." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226196.
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Diploma thesis develops comprehensive documentation of the new building construction of residential house on the level of the implementation of the project construction. Proposal emphasizes layout of linked to ensure the technical design, structural, fire safety, protection against noise, energy saving, safety in use. Work is performed in an electronic format using AutoCAD and Microsoft Word (PDF Creator).
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Hasan, Md Mehadi. "Diffuse sound fields, reverberation-room methods and the effectiveness of reverberation-room designs." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54830.
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The reverberation-room method, which assumes a diffuse sound field, has long been used for various standardized room-acoustical determinations – e.g. of surface-absorption coefficients, power levels of sound sources, transmission losses of acoustical partitions, etc. In this regard, a number of standards have emerged to offer some help by outlining necessary reverberation-room design guidelines to achieve sufficient sound-field diffuseness. However, unsatisfactory opinions regarding the prediction accuracy of the method, especially at low frequencies, have been reported over the years. This might be due to deviations from the assumed diffuse-field concept, which is very challenging to implement from an application point of view; also there are no straight-forward ways to characterize the degree of sound-field diffuseness. To investigate the problem and propose solutions, diffuse-field theory and existing standards have been revisited. Using numerical, finite-element-based, modal prediction, their capacity/effectiveness to achieve a diffuse sound field is analyzed by means of a number of descriptors (room-acoustical parameters). Because of time limitations, the concept regarding the design of a reverberation-room structure – i.e. size, shape, etc. – is mainly explored, rather than the internal test-setup arrangements. The prediction accuracy of different room-acoustical parameters are also determined by the reverberation-room standard methods, with respect to both the Sabine and Eyring versions of the diffuse-field formulae, and both in octave and third-octave bands. The minimum approachable frequencies of predictions and the quality of sound-field diffuseness are discussed in terms of the prediction accuracy of different room-acoustical parameters. Considering three room volumes prescribed by standards, and four room shapes for each of the volumes, it has been found that the reverberation room of volume 150 m³, as prescribed by the ISO 354 standard, with the typical dimensional orientation (longest x-dimension/shortest vertical dimension) yields better field diffuseness than the other rooms of different volumes and shapes. To check the possibility of further improvement of the field diffuseness, a number of additional features are integrated into that reverberation room. It is found that the rooms with diffusers and absorbent corner treatments yield improved sound-field diffuseness, while the rooms with diffuse surface reflection yield poor field diffuseness due to the increased surface absorption.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Shi, Wanqing. "Assessing and modelling impact sound insulation of wooden joist constructions." Licentiate thesis, Luleå tekniska universitet, 1995. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26012.
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Impact sound insulation is one of the most important aspects when assessing sound insulation of floor constructions in buildings. For assessing the impact sound insulation of aconstruction, a standard tapping machine is used as a sound source. However, the use of the current standard tapping machine has been criticised, especially with regard to measurement of wooden joist floors since the noise spectrum generated by a tapping machine differs from the spectrum generated by actual footfall. There are insufficient low frequency components in the noise spectrum produced by the tapping machine and it does not, therefore, accurately reflect low frequency noise from the construction.Reduce impact sound level from wooden joist floors are the main object of our study. It is important to be able to predict the sound insulation properties of wooden joist constructions at the design stage. To reduce the noise level in the receiving room, the input power transmitted through the construction must be estimated where the appropriate sound- and vibration-insulation can be designed.This study has investigated the waveform and frequency spectra of human footfall (walking, rum- ingand jumping); of the dropping of sand balls, sand bags and tires; and of the standard tapping machine. The impact sound power radiation from a wooden joist construction while applying different impact sources, such as actual footfall and the standard tapping machine, have also been studied.Research was also carried out regarding the development of a practical impact sound insulation calculation method for wooden joist floor constructions. The characteristics with regard to mechanical properties of floor construction was calculated using the impedance method. The impact sound level inside the sound receiving room was determined. The method developed can predict the basic performance of the wooden floor structure when excited by impact sounds.Godkänd; 1995; 20070108 (biem)
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Yan, Feng. "The use of passive damping to increase sound insulation in buildings." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31643/.
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This thesis examined the potential sound insulation benefit by using damping material to absorb vibrational energy along its transmission path. Statistical Energy Analysis (SEA) was used to evaluate the effect on system performance of adding damping globally, as well as its influence on individual transmission paths. Nine different theoretical models were studied using both bending only and three-wave SEA models to predict the system behaviour in different frequency regions. The results suggest that global damping treatment generally increases the sound insulation in buildings. Initial increases in the internal loss factor (a term used in SEA to describe material damping properties) were found to provide significant initial improvements in sound insulation and flanking paths as opposed to direct paths were found to benefit more from damping treatment. A simple approximation was proposed to predict the damping benefit of paths of specific order without the need to run a full SEA model. In the presence of heavily damped structural element, where SEA is less likely to provide accurate prediction, a forward ray tracing algorithm was proposed as a supplement. It enables one to predict the energy transmission through a heavily damped component coupling two or more lightly damped components (or SEA subsystems). The energy distribution along the edges of the damped component was studied. The contribution from the direct field was found to dominate the incident energy and resulting transmission, especially in areas close to the source when damping is high. Different passive damping treatment techniques were reviewed as well as the theoretical damping level that is achievable as a guidance for theoretical and experimental validation. Several damping measurement techniques were studied and experimental validation of the ray tracing code was undertaken.
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Öqvist, Rikard. "Measurement and perception of sound insulation from 20 Hz between dwellings." Doctoral thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62843.
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Population growth and urbanization are projected by the United Nations to add 2,5 billionpeople to the world’s urban population by 2050. We need to construct buildings in anunprecedented scale to meet global housing demand. Sustainable development is critical.Compared to traditional heavy constructions, lightweight wooden constructions are moreenvironmentally friendly and will play a key role in meeting future demands. However, thereare two major problems with lightweight constructions that need to be addressed: 1) Limitedlow frequency sound insulation and 2) Variations in sound insulation.Annoyance from walking sound tend to be higher in lightweight than in heavy constructionseven with the same measured sound insulation. The Swedish research program AkuLiteindicated that the correlation between measured sound insulation and annoyance wassignificantly improved by extending current evaluation methods from 50 Hz down to 20 Hz.Secondly, large variations in sound insulation between nominally identical lightweightconstructions are common, which leads to larger safety margins. By identifying and quantifyingunderlying causes, production costs can be minimized and the performance can be improved.The aim of the thesis is to develop a new evaluation method for impact sound insulation thatbetter correspond to rated annoyance, and to identify and control underlying causes forvariations in sound insulation. The thesis contains six papers.In Paper I and II, sound insulation measurements were carried out in a large number ofnominally identical rooms of two different industrially prefabricated lightweight woodenconstructions. The purpose was to assess and quantify the variations in impact and airbornesound insulation. In Paper I, 30 nominally identical apartments of a volume based system wasevaluated. The apartments on the highest floor achieved significantly better sound insulationdue to the extra weight on lower floors affecting the elastic connections between stories. InPaper II, 18 rooms of a cross-laminated timber system of plate elements were evaluated.Additionally, several potential parameters related to measurement uncertainty wereinvestigated.Paper III deals with measurement uncertainty. An empirical study of reverberation timemeasurements showed that current methods need to be improved, if sound insulationrequirements are to be extended to 20 Hz.Paper IV and V verified that the frequency range 20-50 Hz is important for walking soundannoyance, and that alternative frequency adaptation terms can improve the correlation betweenmeasured impact sound insulation and annoyance ratings. In Paper IV, the methodology was toperform extensive field measurements in apartment buildings of various construction types andto perform questionnaire surveys among the residents. In Paper V, the methodology was toevaluate annoyance based on binaural recordings of walking sound in a two-part listening test.In Paper VI, 70 measurements in a lightweight wooden system were evaluated to quantify thetotal variations in impact and airborne sound insulation from 20 and 50 Hz, respectively. It wasconcluded that the proposed metrics of impact sound insulation were primarily determined bythe impact sound level 20-40 Hz and that the measurement methods must be evaluatedthoroughly to avoid excessive safety margins. A new evaluation method for impact sound insulation from 25 Hz, that correspond to the ratedannoyance for both heavy and lightweight constructions is proposed. By using the proposedmethod and attending the specific causes for variations, the lightweight industry will be able todevelop improved multi-story dwellings with higher perceived acoustic quality.Forskningsfinansiärer:
Sven Tyréns Stiftelse
Formas
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Mu, Rui Lin. "Improvement of Sound Insulation Performance of Multi-layer Structures in Buildings." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174914.
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Bull, John Ivan. "Measurement of the airborne sound insulation of traffic noise barriers using impulse response techniques." Thesis, University of Canterbury. Mechanical Engineering, 2014. http://hdl.handle.net/10092/8962.
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This research thesis involves the measurement of the airborne sound insulation of road traffic noise barriers, with the goal of gaining a more in depth understanding of the factors that influence noise barrier performance. A measurement system is developed, based on EN 1793-6:2012, to quantify the airborne sound insulation of a noise barrier in situ. Validation testing is performed to ensure that the system meets the requirements of EN 1793-6:2012. MATLAB code is developed, incorporating all of the signal processing tasks into a single graphical user interface. The measurement system is then used to measure the airborne sound insulation of eight existing traffic noise barriers located around Auckland, New Zealand.
The results from the Auckland field tests show that consistent single number ratings of airborne sound insulation can be achieved on different samples of the same noise barrier. The presence of air gaps and hidden defects will degrade the acoustic performance of a noise barrier, most significantly at the high frequencies. The comparison of single number ratings calculated with differing measurement frequency ranges is discussed, and some comments are made on the measurement standard itself.
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Balilah, Y. A. "The use of impulse techniques in the measurement of sound insulation in buildings." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234843.
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Ingham, James. "Sound worlds and everyday space." Thesis, University of East London, 1999. http://roar.uel.ac.uk/1251/.
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The starting point for this project was my MPhil thesis (University of Leeds, 1995) Aural Geographies. An Investigation of Sound In Everyday Space, which has as its subject matter the concept of sound in everyday space. The MPhil thesis argued that in considering everyday space more attention should be paid to the aural experience. The argument did not try to `bolt on' what is heard to what is seen. Rather it contemplated the intricate relationships between the visual and aural senses within everyday space. Following from the work which was undertaken for the MPhil it became clear that further and more substantial research into the area of sound and space was merited. This research has been carried out at the University of East London as a PhD programme, under the supervision of Professor Andrew Blake, who introduced me to numerous aspects of music analysis. The thesis acknowledges and expands upon the work on sound carried out by the limited number of social theorists who have addressed this issue such as Adorno, Attali and in particular Schafer and his work on soundscapes. There is discussion throughout of the inspirational ideas of John Cage. The aim of the thesis, which is explored through many inter-related pieces of analysis and empirical work, is to expand upon our knowledge of the role of sound in everyday life. The thesis contributes towards knowledge by providing many new insights about the soundworld and its place in human experience. As befits a thesis which centres on the aural, the research methods are also innovatory allowing the readers/listeners themselves to experience sound worlds. The thesis therefore relies 111 heavily on newly-developed new recording/mapping techniques, using high quality audio recordings which are then used to produce digital sound maps in the form of hypermedia made available on a CD-ROM. The thesis demonstrates how these maps enable us to comprehend some of the complex sensory processes associated with sound worlds. Sound worlds are the main focus here, and in particular the way in which sound worlds are constructed by individuals. Where the MPhil examined sound in public spaces, this thesis further reflects on that investigation before going on to investigate the sound worlds generated in the living room (a key everyday space). This enables us to hear/see how the sound worlds associated with the living room link up with other everyday spaces. The contention is that sound is crucial for the organisation and operation of everyday space Though the thesis is persuasive in indicating the importance of the aural in everyday life, the question arises as to how the relationship between the aural and the visual can be represented in academic work, and especially in the discipline of geography. This question is addressed in the thesis by the presentation of a number of specially developed aural terms, such as `sonic order' and `sound maps'. The thesis describes how people organise their activities around sonic order, and explains how conflicts arise over sonic order. The thesis concludes that sound maps are present in everyday space and that people use them to navigate everyday space. This sensitivity to sound spaces generates geographical (aur/imagin)ations, which are in turn subject to study from within the discipline of geography.
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Lester, Martin Richard. "Selective intensimetry for the measurement of sound radiation from building elements." Thesis, Liverpool John Moores University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294022.
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Pavasovic, Vladimir, and vpavasovic@wmgacoustics com au. "The radiation of Sound from Surfaces at Grazing Angles of Incidence." RMIT University. Applied Sciences, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20060911.115939.
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It is difficult to predict the sound radiation from large factory roofs. The existing infinite panel theories of sound insulation are not sufficient when the sound radiates at grazing angles. It has been shown that the reason for the collapse of the theory is the well known result for the radiation efficiency. This research will present a simple analytic strip theory, which agrees reasonably well with numerical calculations for a rectangular panel. Simple analytic strip theory has lead to the conclusion that it is mainly the length of the panel in the direction of radiation, rather than its width that is important in determining its radiation efficiency. The findings of the current research also indicated that apart from the effect due to coincidence, a panel was non-directional compared to an opening.
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Hall, Robin. "Impact sound insulation of flooring systems with polyurethane foam on concrete floors." Thesis, Sheffield Hallam University, 1999. http://shura.shu.ac.uk/3135/.
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The problem of unwanted noise in buildings has grown continuously over the last twenty years and impact noise through separating floors has been identified as a particularly important problem. One accepted method for improving impact sound insulation is to use floating floors in which the walking surfaces are isolated from the supporting structure by a resilient layer. Traditionally the resilient layers comprise mineral or glass fibre quilts but other materials such as flooring grade polystyrene are increasingly used. Recently, shallow profile floating floors comprising flexible open cell polyurethane foam resilient layers have been developed. These systems are attractive for refurbishment projects since they can simply be placed on existing floors in order to improve their impact sound insulation whilst raising the existing floor level less than systems comprising fibre quilts. Shallow profile floating floors with thin layers of flexible open cell polyurethane foam are the subject of investigation as part of this research work. This thesis reviews the previous research on polyurethane foams and evaluates the usefulness of the Standard Tests on these materials for assisting in the selection of foam for use as resilient layers under lightweight floors. Both the static and dynamic behaviour of flexible open cell polyurethane foam are investigated and recycled polyurethane foam is shown to be particularly useful for use under floating floors Its characteristic behaviour under compressive strain is described for the first time. This thesis shows that by modifying the Standard Method for the determinaf on of the dynamic stiffness of resilient layers under floating floors (BS EN 29052-1), the effect of the air contained in the open cell foam specimens can be included in the Standard laboratory test. The modification makes it possible to evaluate the dynamic stiffness of low airflow resistivity resilient polyurethane resilient layers using the apparatus described in BS EN 29052-1 for the first time. Field measurements of impact sound pressure level conducted using sections of lightweight shallow profile floating floor on a concrete supporting floor are described. The measured improvements in impact sound insulation achieved by using the sections of floating floor are compared with the improvements predicted using the results from the modified Standard laboratory tests on the foams used as resilient layers. It is shown that by compensating for the mass impedance of the Standard tapping machine hammers good correlation between predicted and measured data is achieved. A simple method for predicting the weighted standardised impact sound pressure level (L'nT,w) in the receiving room is proposed which shows excellent correlation with L'nT,w obtained from the measured data. The work shows that BS EN 29052-1 is more widely applicable than the Standard itself states and for the first time identifies a method of predicting the performance of lightweight shallow profile floating floors with polyurethane foam resilient layers. Finally the use of the ISO tapping machine for assessing the impact sound insulation of the very lightweight floating floors of interest to this research is considered. Different methods of correlating perceived and measured the impact sound insulation of floors are reviewed. Experimental results conducted in this research programme, along with searches of the literature confirm that the tapping machine is a suitable source for measuring the impact sound insulation of these floors.
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Anani, John Kodjo. "A subjective and objective assessment of sound insulation in newly converted dwellings." Thesis, Open University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316964.
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Whitfield, William. "Uncertainty associated with the measurement of airborne sound insulation in the field." Thesis, University of Liverpool, 2013. http://livrepository.liverpool.ac.uk/14517/.
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Understanding uncertainty is an important part of any scientific measurement process and the ability to evaluate and understand uncertainty is a requirement of the International Standards for quality control. The basic uncertainties relating to the measurement of airborne sound insulation in the field can be assessed using the methods in BS5725. However, identifying the components that contribute to the total variability is beyond the scope of the standard and more detailed information requires a more advanced approach. Recent developments in the “Guide to the expression of uncertainty in measurement” (GUM) suggest an approach can be used where identification of the input variables and their likely contribution will result in a solution that can be modelled providing enough information is available. However, recent research on uncertainty in sound insulation using GUM has identified problems involving the correlation between frequency bands, which leads to an overestimate of uncertainty. An empirical approach is used in this thesis, which incorporates advanced analysis of variance (ANOVA) and a specific model called Gauge Repeatability and Reproducibility (GRR). It enables the components of variance in the measurement system to be partitioned and provides an estimate of their contribution. In addition, ANOVA highlights any interaction between factors. In the GRR, carried out on a lightweight timber floor and a heavyweight concrete floor, significant interaction was detected between the operator and part. Good agreement is obtained in the repeatability and reproducibility calculated for each construction and the samples are combined with measurements of test elements that provide a wider range of sound insulation performance. The uncertainty associated with the instrumentation, operator, interaction and part are calculated in each case. It is shown that the interaction component is important and should be contained in any approach evaluating uncertainty. Further evidence reveals that the total uncertainty in the measurement process is dependent on the construction being measured.
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Fazenda, Bruno M. "Perception of room modes in critical listening spaces." Thesis, University of Salford, 2004. http://usir.salford.ac.uk/1828/.
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Room modes are a recognised problem in small critical listening rooms and are known to cause colouration of sound reproduced within them. Investigations on the causes and solutions for this problem have been carried out for some time. Interest in the topic has extended to loudspeaker manufacturers who have mainly concentrated in developing methods for controlling the loudspeaker-room interaction in order to ameliorate low frequency reproduction. Compared to objective work on passive and active control methods, the study of the subjective perception of room resonances has been somewhat neglected. Available publications mostly concern the effects of single resonances, which are perhaps not fully representative of conditions as experienced in real rooms. A study into the subjective perception of room modes is presented. The experimental methodology employs psychoacoustic techniques to study the perception of factors such as modal distribution, and effects of resonances on single tones. Results show that the subjective perception of room modes is strongly affected by temporal issues, and that changes exerted merely on magnitude frequency response are detectable but not likely to remove the effects of resonances for all listeners. Furthermore, it is shown that a reduction of the modal Q-factor, associated with a reduction of decay rates, has a significant effect in decreasing the detection of resonances. Q-factor difference limen were evaluated for three reference decay characteristics corresponding to reference Q-factors of 30, 10 and 1. The limen were 6±2.8, 10±4.1 and 16±5.4 respectively, meaning that detection of changes to modal decay decreases with decreasing decay time. These results may be used to define more perceptually relevant design guidelines for critical listening environments, and indicate target criteria for control techniques used in room correction. The outcomes of this investigation will have repercussions on the design of better rooms for critical listening.
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Morgan, Julian Rees. "Selective estimation of sound pressure and intensity in determinations of transmission loss." Thesis, Liverpool John Moores University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253702.
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Mason, James Meredith. "A reciprocity technique for the characterisation of sound transmission into aircraft fuselages." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254602.
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Round, David Peter. "Application of DSP methods to sound reproduction." Thesis, Bangor University, 1996. https://research.bangor.ac.uk/portal/en/theses/application-of-dsp-methods-to-sound-reproduction(89e56009-ab09-4054-9a6b-e5181507a3f4).html.
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Shimizu, Takafumi. "Study on improvement of sound insulation performance for multi-layer windowpanes and gaps." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215221.
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Wolf, Michal. "Mateřská škola." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227283.
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Master´s thesis deals with the processing of building part of the project documentation for building construction. The aim of the Master´s thesis is a new building of kindergarten in the village Dolany near Olomouc. The building is designed for 40 preschool children. The building is situated near the centre of the village and is easily accessible from surrounding living areas. The building is partly basement and has two floors. In the basement there are technical equipments and storages. In the floors there are classes for children and areas ensuring the service of kindergarten. This masonry building is insulated with contact thermal insulation system and roofed with a warm flat roof.
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McKell, Bernadette. "The development of a screening test to determine the impact sound insulation of floors." Thesis, Heriot-Watt University, 1991. http://hdl.handle.net/10399/823.
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Blomgren, Linnea. "A room of one's own : woven structures." Thesis, Konstfack, Textil, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-5425.
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I have explored the combination of sound, textile and space. How can one create textiles to use as sound dampening material in an arts and craft practice? To enhance the architectural aspect of textile as one of the five building materials I have chosen to weave walls. Walls don´t have to be straight or go from floor to ceiling but they should somehow create room and divide the space. I felt the need of walls working within Konstfack because of the distraction of fellow students in the open space classroom. Torn walls tells a story, we see the left traces. These traces I wanted to convert into woven textile. Sounds of people and objects in public spaces bounces between hard surfaces often without dampening, this creates an environment that causes stress and distraction. In Virginia Wolf´s essay “A room of Ones Own” (1929) she points at how important it is to create a workspace for the professional you, to take place and be part of the public realm. A big part of this master project has been making the actual materials to build with and executing fibre. Does the material do the job of sound absorption? Wool and silk both have a fibrous cell, which is suitable for sound absorption they also have low flammability and is biodegradable; therefore I chose to work mainly with these fibres. I share my knowledge through the experience of the space I create. How to create o Room of one´s own in an open office.
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Klepko, John. "Acoustical optimization of control room 'A' at the McGill University Recording Studios." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22439.
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The loudspeaker system and the room interface are the two main components in any listening environment. Research will be conducted focusing on the room component using Control Room 'A' of the McGill University Recording Studio in an attempt to optimize the monitoring situation. The sound field of the room will be broken down and analyzed in both time and frequency domains. The problem areas of the room will be identified and the surfaces altered by means of absorption, reflection and diffusion.
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Wu, Tsan-Ming. "Statistical impulse reponse modeling and dereverberation for room acoustics." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/14932.
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Melo, Gustavo da Silva Vieira de. "Measurement and prediction of sound absorption of room surfaces and contents at low frequencies." Florianópolis, SC, 2002. http://repositorio.ufsc.br/xmlui/handle/123456789/84349.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Mecânica.Made available in DSpace on 2012-10-20T08:32:17Z (GMT). No. of bitstreams: 1 188655.pdf: 9575761 bytes, checksum: 78ad975fff9c15d8b5ba76309b3a5dd2 (MD5)
Na área de transmissão sonora em edificações, uma recente ênfase tem sido dada ao estudo de freqüências audíveis, abaixo de 100 Hz. Isto se deve ao aumento do número de fontes de ruído de baixa freqüência, tais como uso de aparelhos domésticos de som ou TV com a capacidade de emitir sons graves cada vez mais potentes, etc. Existe uma preocupação especial com ruídos de baixa freqüência devido a sua eficiente propagação através do ar e eficácia reduzida de sua atenuação por parte de várias estruturas, como por exemplo, protetores auditivos e paredes entre residências. Contudo, em baixas freqüências, as abordagens teóricas mais utilizadas apresentam deficiências explicativas sobre a realidade estudada e precisam ser aprimoradas. Adicionalmente, observa-se que as normas referentes a isolamento sonoro não abrangem a região de freqüências abaixo de 100 Hz e nem mesmo a introdução do Anexo F da norma ISO 140/3 (1995) foi capaz de garantir um nível adequado de reprodutibilidade dos resultados. Nesse sentido, modelos de transmissão sonora entre salas que utilizam técnicas de EF têm demonstrado as características modais dos campos acústicos e vibratórios envolvidos no sistema sala-parede-sala, indicando a necessidade de modelos apropriados para a absorção sonora em baixas freqüências. Neste trabalho um novo modelo de EF foi utilizado para descrever as relações entre as características de absorção sonora das superfícies internas de uma sala e a resposta em freqüência desta sala, para o intervalo de freqüências de 20 Hz a 200 Hz. Inicialmente, o modelo numérico foi validado por comparação com resultados experimentais para uma pequena câmara reverberante vazia, denominada sala de referência. Adicionalmente, investigou-se o efeito da introdução de elementos de mobília no interior da sala, os quais foram abordados como obstáculos rígidos e macios, a fim de verificar possíveis modificações nas freqüências naturais e amortecimento seletivo dos modos do sistema. O efeito da localização de tais obstáculos também foi incluído nas investigações. Os resultados obtidos apresentaram um grau de concordância satisfatório entre valores medidos e simulados, permitindo a conclusão de que a absorção sonora não modifica significativamente as respostas em freqüência da sala em baixas freqüências.
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Sanguinetti, Mahela. "Measuring hearing protection performance results in a MIRE-compliant reverberatory chamber versus a non-MIRE compliant room." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5564.
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Thesis (M.S.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains iii, 44 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 42-44).
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LIN, FANG-MING, and 林芳銘. "Research on the sound insulation capability of walls in buildings:measurement and evaluation of sound insulation of walls by sound intensity Method." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/56259341963059847004.
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Chen, Ping-Chung, and 陳炳全. "An airborne sound insulation and sound absorption analysis in situ measurements." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/50644816306294052938.
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碩士國立臺灣海洋大學
系統工程暨造船學系
99
This thesis is to study the sound insulation and sound absorption of acoustic materials which is used to buildings and roadway engineering. In order to understanding the acoustic insulation materials property, the acoustic measurement experiments must be carried out in the standard laboratory . The measurement values are sound transmission loss and the sound absorption coefficients with a reverberation room method or the impedance tube method. Also, in this thesis quote the norm prCEN/TS 1793 Road Traffic Noise Reducing Devices-Test Method for determining the acoustic performance-Part 5:Intrinsic characteristics-In situ values of sound reflection and airborne sound insulation , we can confer the material effect which is installed actually . The in-situ measurement is an analysis that produce an impulse response with the temporal signal, use a maximum-length sequence (MLS) as the standard test signal , we also join the Adrienne temporal window and signal subtraction technique to calculate the values of sound insulation index and sound absorption. The comparison and discussion are finished with the results of experimentation in laboratory . We can understand the effects of reducing noise that the materials is at the scene and the laboratory, and also can get the relative relation between the both results.
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Tarng, Ming-Jhih, and 唐明志. "Sound Insulation Characteristics of Honeycomb Sandwich Panels." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/62847748383507787574.
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碩士國立臺灣大學
工程科學及海洋工程學研究所
93
The purpose of this research is to discuss the sound insulation characteristics of honeycomb sandwich panel. At first, the sandwich panel is made of layered media and the center core was regarded as an elastic porous material. Thus, the Biot theory could be employed to analyze the waves propagated in fluid saturated porous material. The transfer matrix for waves propagated between two ends of the sandwich panel was established. The combination of these related matrices can be applied to evaluate the transmission loss. To order to verify the present method, four sandwich panels which were measured by Moore are analyzed. The comparison of the transmission loss between experimental data and numerical predictions is reliable except the Panel D. In the case of Panel D, the fundamental settings are different from present method in this thesis. Using the present method, several cases are set up to investigate related parameters of cores, such as thickness, density and cell size. The numerical results show that the coincident frequency will change with different thickness of the core and this variance in frequency will influence the sound insulation of the panel. In addition, the effect of core density is similar to the effect of core thickness. The coincident frequency will decrease with the increase of the core density until the core density increase to exceed certain limit. At the time, the coincidence will occur in the same frequency. Finally, cell size of the core doesn’t influence the transmission loss of sandwich panels.
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Li, Yuan-Wei, and 李芫維. "Sound insulation performance of double-leaf panel." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/gh6hme.
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碩士國立臺灣大學
工程科學及海洋工程學研究所
107
The purpose of this research is to discuss the sound insulation of double-leaf panel. In the actual production of panels and experimental measurements, the middle part of the double-leaf panel needs to be connected by studs. Then the way of connection divided of points and line. The sound insulation quantity of different connection methods is not the same. In this thesis, we use the governing equation to simulate the sound insulation performance of double-leaf panel, while the middle structure is simulated by springs. With the difference of the incident frequency, the stiffness of the spring is also different. Based on the literature proposed to distribution of spring stiffness values, into the theoretical calculation to simulate the sound insulation performance of double-leaf panel. To order to verify the present method, citing data measured by NRCC. The comparison of the transmission loss between experimental data and numerical predictions is reliable. Using the present method, several cases are set up to investigate related parameters of double-leaf panel, such as thickness, density, stud spacing, distance between two panels and add some porous between two panels. The numerical results show that the coincident frequency will change with different thickness of the panel. Finally, theoretical analysis show that add porous to the structure can increase the sound insulation by about 5 dB.
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He, Yu-Wei, and 何育蔚. "Research of Resilient Material on Sound Insulation with Residential Floor Impact Sound." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/05694562208148809795.
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碩士國立臺灣海洋大學
系統工程暨造船學系
103
In recent years, people began to pay attention to the quality of the living environment of home. Not just the interference of horizontal neighborhood noise, the concerned about vertical floor impact sound has become upward. The dispute cause by residential floor impact sound often happen. Domestic standard floor impact sound measurement labs are few. In order to improve the interference of impact sound to residential floor, in this study we build a imitate-standard double reverberation chambers without the flanking sound effects. Take the spatial correction and comparison of sound field property with a series of experimental groups test. We make sure the floor impact sound experimental can be used. Since existing floor is not easy to change, we often cover resilient materials over the floor to improve the impact noise. We provided a complete floor impact sound insulation indexes of raised floor and resilient materials through a series of experiments.
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Ressl, Waqar-Un-Nissa (Vicky). "Room sound field prediction for auralization." Thesis, 1997. http://hdl.handle.net/2429/7397.
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Sound fields in rooms, including the complex interactions between propagating sound
waves and the room surfaces, are predicted using various approaches. These approaches are validated either physically - by comparing the measured and predicted sound fields - or subjectively. Subjective evaluation of the predictions can be performed using auralization, which consists of simulating an acoustical environment for binaural presentation to a listener.
Inaccuracies that result from the different sound-field prediction methods result in imperfect auralization. It is of interest to understand the perceptual consequences of these inaccuracies and compensate for them with accurate sound-field prediction models. The aim of this research project was to develop accurate sound-field prediction models for use in auralization systems. To achieve this objective, two phases of work were undertaken: (1) acoustical signals were created, using simplified sound-field techniques, and presented to listeners using
a commercial auralization system in order to test sound-localization ability; (2) a soundprediction algorithm was derived and used in the development of an improved roomprediction model. With respect to the work using the commercial auralization system, modifications were made to the system to mimic higher-order reflections in the room, as well as to account for varying surface absorption in each octave band. Subjects' localization abilities were evaluated using the sound-field simulations and in a real room to validate the
sound-field simulations. Inconclusive results from the localization tests led to the development of an improved sound-field prediction model based on acoustical radiosity. The radiosity model was validated experimentally in full-scale and scale-model rooms with the help of other prediction models. A combined model - based on the method of images and radiosity - was developed and validated in several rooms. An inherent attribute of the radiosity approach which makes it unsuitable for auralization was identified.
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Chueh-HsienHuang and 黃覺賢. "A Study on Sound Insulation of Movable Partition." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/90386691974285619324.
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