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Melody spotting using hidden Markov modelsDurey, Adriane Swalm, January 2003 (has links) (PDF)
Thesis (Ph. D.)--School of Electrical and Computer Engineering, Georgia Institute of Technology, 2004. Directed by Mark A. Clements. / Vita. Includes bibliographical references (leaves 176-184).
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Responses of hot wire to acoustic excitations /Ho, Kai-kwong. January 1980 (has links)
Thesis--M. Phil., University of Hong Kong, 1980.
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Experimental study of sound waves in sandy sediment /Yargus, Michael W. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 67-70).
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Responses of hot wire to acoustic excitations何啓光, Ho, Kai-kwong. January 1980 (has links)
published_or_final_version / Mechanical Engineering / Master / Master of Philosophy
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An integrated system for dynamic control of auditory perspective in a multichannel sound field /Corey, Jason Andrew January 2002 (has links)
An integrated system providing dynamic control of sound source azimuth, distance and proximity to a room boundary within a simulated acoustic space is proposed for use in multichannel music and film sound production. The system has been investigated, implemented, and psychoacoustically tested within the ITU-R BS.775 recommended five-channel (3/2) loudspeaker layout. The work brings together physical and perceptual models of room simulation to allow dynamic placement of virtual sound sources at any location of a simulated space within the horizontal plane. / The control system incorporates a number of modules including simulated room modes, "fuzzy" sources, and tracking early reflections, whose parameters are dynamically changed according to sound source location within the simulated space. The control functions of the basic elements, derived from theories of perception of a source in a real room, have been carefully tuned to provide efficient, effective, and intuitive control of a sound source's perceived location. / Seven formal listening tests were conducted to evaluate the effectiveness of the algorithm design choices. The tests evaluated: (1) loudness calibration of multichannel sound images; (2) the effectiveness of distance control; (3) the resolution of distance control provided by the system; (4) the effectiveness of the proposed system when compared to a commercially available multichannel room simulation system in terms of control of source distance and proximity to a room boundary; (5) the role of tracking early reflection patterns on the perception of sound source distance; (6) the role of tracking early reflection patterns on the perception of lateral phantom images. / The listening tests confirm the effectiveness of the system for control of perceived sound source distance, proximity to room boundaries, and azimuth, through fine, dynamic adjustment of parameters according to source location. All of the parameters are grouped and controlled together to create a perceptually strong impression of source location and movement within a simulated space.
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Prediction of sound pressure and intensity fields in rooms and near surfaces by ray tracingCousins, Owen Mathew 11 1900 (has links)
The health, safety, comfort and productivity of a room’s occupants is greatly influenced by the sound field within it. An acoustical engineer is often consulted during the design of a room to prevent or alleviate unwanted acoustical problems. Prediction models are often used to find the most cost-effective solution to a given acoustical problem. The accuracy of sound-field prediction varies with the particular model, as do the parameters predicted. Most models only predict sound-pressure levels. Many only predict energetic quantities, ignoring wave phase and, therefore, interference and modal effects in rooms. A ray-tracing model, capable of predicting sound-pressure level, reverberation time and lateral energy fraction was translated into MATLAB code and modified to increase accuracy by including phase. Modifications included phase effects due to path length travelled and phase changes imparted by surface reflections as described by complex reflection coefficients. Further modifications included predicting steady-state and transient sound-intensity levels, providing information on the direction of sound-energy flow. The modifications were validated in comparison with free-field theory and theoretical predictions of sound fields in the presence of a single surface. The complex reflection coefficients of four common building materials were measured using two methods—an impedance tube and the spherical-decoupling method. Using these coefficients, the modified program was compared with experimental data measured in configurations involving one or more surfaces made of these materials, in an anechoic chamber, a scale-model room, and a full-scale office space. Prediction accuracy in the anechoic chamber, and in the presence of a single reflecting surface, greatly improved with the inclusion of phase. Further comparison with full-scale rooms is required before the accuracy of the model in such rooms can be evaluated definitively.
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Sound transmission analysis by sound intensimetry.Van Zyl, Barend Gideon. January 1985 (has links)
This thesis represents the development and evaluation of a theory for
sound transmission analysis by sound intensimetry. In the context of
this study sound transmission analysis is understood to embrace the
following:
(1) The measurement of sound reduction indices.
(2) Diagnostic analysis of sound transmission through panels and
structures.
The sound intensity method is examined against the theoretical background
of the classic two-room method which forms the basis of currently
used international standards. The flanking problem, which is one of
the principle limiting factors in the use of the classic method, is
analyzed.
The standard formulation of the intensity method is expanded to account
for leakage error, boundary interference effects and calibration mismatch.
It is shown that the commonly observed low-frequency discrepancy
between intensity and classic method results is resolved by application
of the Waterhouse correction.
Sound absorption by the test object on the receiving side is shown to
cause an error which increases with the flanking factor and with the
fraction of the receiving room absorption located on the surface of the
test object. Guidelines are developed for the assessment and control
of absorption error in practical situations.
Using the common mode rejection index as a performance rating for sound
intensity meters, the measurement of sound transmission in reactive
fields is investigated. Derivation of a formula for the reactivity
near the surface of a transmitting panel surrounded by a flanking
structure in a reverberant field, leads to the development of a theoretical
framework and criteria for the planning and evaluation of test
arrangements for sound transmission analysis. Guidelines are given for
the calculation of minimum receiving room absorption and the microphone
spacing required in practical situations.
A study of the characteristic properties of sound intensity fields in
diffuse and non-diffuse environments is used as a basis in formulating
a new method of measuring directional diffusivity. Based on the relationship
between reactivity and the degree of directional balance in a
sound intensity field, this method involves spatial averaging of the
pressure level and determination of the magnitude of the total
intensity vector at the point under consideration. A direct-reading
diffusivity meter has been developed and employed in assessing
diffusivity in practical situations.
The effect of a lack of directional diffusivity on the accuracy of
sound transmission analysis in reactive fields is examined. Criteria
for calculating minimum diffusivity requirements in the source and receiving
room are developed and evaluated experimentally. / Thesis (Ph.D.)-University of Natal, 1985.
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Optimization of digital audio for Internet transmissionHans, Mathieu Claude 05 1900 (has links)
No description available.
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An experimental investigation of the anomalous behavior of underwater acoustic volume displacement sensorsGray, Michael Dean 05 1900 (has links)
No description available.
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Scale model experiments on the diffraction and scattering of sound by geometrical step discontinuities and curved rough surfacesChambers, James P. 08 1900 (has links)
No description available.
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