Globally, the ever increasing consumer interest in multichannel audio is a major factor driving the research intent in soundfield reconstruction and compression. The popularity of the well commercialized 5.1 surround sound system and its 6-Channel audio has been strongly supported by the advent of powerful storage medium, DVD, as well as the use of efficient telecommunication techniques. However, this popularity has also revealed potential problems in the development of soundfield systems. Firstly, currently available soundfield systems have rather poor compatibility with irregular speaker arrangements. Secondly, bandwidth requirement is dramatically increased for multichannel audio representation with good temporal and spatial fidelity. This master???s thesis addresses these two major issues in soundfield systems. It introduces a new approach to analyze and sysnthesize soundfield, and compares this approach with currently popular systems. To facilitate this comparison, the behavior of soundfield has been reviewed from both physical and psychoacoustic perspectives, along with an extensive study of past and present soundfield systems and multichannel audio compression algorithms. The 1th order High Spatial Resolution (HSR) soundfield recording and reproduction has been implemented in this project, and subjectively evaluated using a series of MUSHRA tests to finalize the comparison.

Typescript (photocopy) / xvi, 339 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Mechanical Engineering, University of Adelaide, 1979

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.

The sound transmission loss characteristics of plywood based sandwich panels were investigated. Measurements were made of the sound transmission loss of a range of materials and used as a baseline for comparison while a sound transmission loss optimisation method was developed. A unique test rig was built and calibrated to determine selected mechanical properties of materials of interest. The results of sound transmission loss and material properties measurements were used to select an appropriate prediction model, which was then used in conjunction with a mathematical optimisation model to determine combinations of materials and panel parameters which result in improved sound transmission loss. An effort was made to reproduce these predictions in experimental testing by constructing several prototype panels.

Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Vita. / Includes bibliographical references. / by James Moore. / Ph.D.

Includes bibliography. / 374 leaves, [7] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 1985

J.R. Pellam. / "November 25, 1948." / Bibliography: p. 22. / Army Signal Corps Contract No. W36-039-sc-32037 Project No. 102B. Dept. of the Army Project No. 3-99-10-022.

The Riverside Energy Efficiency Laboratory at Texas A&M University conducts sound quality testing for the Home Ventilating Institute. When the Home Ventilating Institute initially established their sound quality test, the semi-reverberant sound chamber to conduct the sound quality tests was built at the Riverside Energy Efficiency Laboratory. The Home Ventilating Institute created a standard to specify the procedure for sound quality testing. This standard contained high consideration for performance, reliability, and accuracy. The standard was based on several ANSI standards for sound testing procedures, sound setup and equipment standards, and sound rating calculations. The Riverside Energy Efficiency Laboratory presently continues sound quality testing for the Home Ventilating Institute using the semi-reverberant sound chamber. The standard has been revised and updated due to developments for better sound quality test result representation. Resourceful data to assist with further developments comes from the semi-reverberant sound chamber's characteristics. This thesis's purpose was to conduct an analysis of the performance for the semi-reverberant sound chamber. The sound chamber's sound transmission loss was determined using a fan source with known sound power across the 24 tested 1/3 octave frequency bands, 50 Hz - 10,000 Hz. The sound pressure was recorded inside the chamber and outside the chamber at the sound source. The sound source was placed at three different locations around the sound chamber. In addition, the sound pressure was measured in real time to study the amount of sound pressure fluctuation and maximum amplitude. The background noise was measured inside the sound chamber for these tests. The sound transmission loss profiles were identical for each location. The lowest two 1/3 octave bands, 50 Hz and 63 Hz, have low transmission losses. The profile jumps up at the following 1/3 octave band and increases with a peak around 1600 Hz before slightly decreasing. The profile of the sound pressure in the time domain showed similar results. The most fluctuation with the greatest peaks was present in the lower 1/3 octave frequency bands, and diminished the higher the 1/3 octave frequency band. Sound sources around the sound chamber can be evaluated to determine whether an impact is possible on the sound quality tests from these results. The impact of modifications to the sound chamber can use the transmission loss values to help determine the expected performance increase.

Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Rogers, P. H.; Committee Member: Ferri, A. A.; Committee Member: Ruzzene, M.; Committee Member: Smith, M. K.; Committee Member: Trivett, D.; Committee Member: Zinn, B. T. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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