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1

Burkhard, Mahlon D. "Acoustical standards in engineering acoustics." Journal of the Acoustical Society of America 115, no. 5 (May 2004): 2434. http://dx.doi.org/10.1121/1.4781590.

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2

Molevich, Nonna E., Anatoly I. Klimov, and Vladimir G. Makaryan. "Influence of Thermodynamic Nonequilibrium on the Acoustic Properties of Gases." International Journal of Aeroacoustics 4, no. 3 (July 2005): 373–83. http://dx.doi.org/10.1260/1475472054771411.

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This paper is a brief review of results of experimental and theoretical studies in the field of acoustics of nonequilibrium gas-plasma media. New acoustical properties of nonequilibrium media caused by the change in sign of the second viscosity and the dispersion coefficients are considered. Such media are acoustically active. Conditions are discussed for generating new nonlinear acoustical structures.
3

Van Uffelen, Lora, James H. Miller, and Gopu R. Potty. "Underwater acoustics and ocean engineering at the University of Rhode Island." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A124. http://dx.doi.org/10.1121/10.0015761.

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Underwater acoustics is one of the primary areas of emphasis in the Ocean Engineering Department at the University of Rhode Island, the first Ocean Engineering program in the United States. The program offers Bachelors, Masters (thesis and non-thesis options) and PhD degrees in Ocean Engineering. These programs are based at the Narragansett Bay campus, providing access to a living laboratory for student learning. Some key facilities of the program are an acoustics tank and a 100-foot-long wave tank. At the graduate level, students are actively involved in research focused in areas such as acoustical oceanography, propagation modeling, geoacoustic inversion, marine mammal acoustics, ocean acoustic instrumentation, and transducers. An overview of classroom learning and ongoing research will be provided, along with information regarding the requirements of entry into the program.
4

Brown, David A., Paul J. Gendron, and John R. Buck. "Graduate education in acoustic engineering, transduction, and signal processing University of Massachusetts Dartmouth." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A123. http://dx.doi.org/10.1121/10.0015756.

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The University of Massachusetts Dartmouth has an established graduate program of study with a concentration in Applied Acoustics leading to the M.S. and Ph.D. degree in Electrical Engineering. The program offers courses and research opportunities in the area of electroacoustic transduction, underwater acoustics, and signal processing. Courses include the Fundamentals of Acoustics, Random Signals, Underwater Acoustics, Introduction to Transducers, Electroacoustic Transduction, Medical Ultrasonics, Digital Signal Processing, Detection Theory, and Estimation Theory. The ECE department established the university’s indoor underwater acoustic test and calibration facility which is one of the largest academic facilities supporting undergraduate and graduate thesis and sponsored research. The department has collaborations with many marine acoustic related companies including nearby Naval Undersea Warfare Center in Newport, RI and Woods Hole Oceanographic Institute in Cape Cod, MA. The presentation will highlight recent theses and dissertations, course offerings, and industry and government collaborations that support acoustical engineering, transduction, and signal processing.
5

Fonseca, William D'Andrea, Eric Brandão, Paulo H. Mareze, Viviane S. G. Melo, Roberto A. Tenenbaum, Christian dos Santos, and Dinara Paixão. "Acoustical engineering: A complete academic undergraduate program in Brazil." Journal of the Acoustical Society of America 152, no. 2 (August 2022): 1180–91. http://dx.doi.org/10.1121/10.0013570.

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Acoustics is a broad field of knowledge that extends branches all over the physics of wave phenomena, psychology, natural sciences, and engineering. It is taught, in general, as part of engineering, physics, or architecture programs, or even in graduate programs specialized in the theme. In Brazil, acoustics was taught in graduate programs, until the creation of Acoustical Engineering in 2009, at the Federal University of Santa Maria, an integral undergraduate program dedicated to acoustics, audio, and vibration (lasting ten semesters). This article presents its complete academic program, its creation process, and the professional establishment of the acoustical engineer. In the following, the program of study and subjects are elucidated and detailed, and the teaching methodologies used are also discussed. The program employs several active learning strategies, like project-based learning, aiming to transform abstract into concrete knowledge. The interaction of the university, the acoustical engineer, and society is also presented and clarified. The placement of graduates in fields and their workplaces are presented as outcomes. As a fundamental part of the engineer's formation, the infrastructure used, whether state-of-the-art or cost-effective equipment, is detailed in the context of teaching and research. Finally, some of the ongoing research projects of the students are described.
6

Hioka, Yusuke, Michael Kingan, and George Dodd. "Learning effect of active learning coursework in engineering acoustics course." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 2 (August 1, 2021): 4154–65. http://dx.doi.org/10.3397/in-2021-2617.

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This paper reports the learning effect achieved by a newly developed coursework for an engineering acoustics course offered to fourth year and postgraduate engineering students at the University of Auckland, New Zealand. The course teaches fundamental knowledge that acoustical engineers need and which underpins a variety of sub-disciplines in acoustics including: fundamental physics of wave propagation, building and room acoustics, electro-acoustics, audio signal processing, and the psychology of hearing. The coursework incorporated practical active learning activities and was developed in order to help students gain understanding of complex concepts related to the room acoustics measurement and analysis. The coursework also has the goal of providing students with an introduction to some of the practical tasks which are typical of a practising acoustical engineering in New Zealand. The learning effect was measured by comparing students' performance in a quiz that was run before students commenced working on the coursework and that in the final examination and by investigating common mistakes students made in the report which was the required deliverable of the coursework. Overall, the new coursework successfully improved students' understanding of the material which it covered.
7

Hiremath, Nandeesh, Vaibhav Kumar, Nicholas Motahari, and Dhwanil Shukla. "An Overview of Acoustic Impedance Measurement Techniques and Future Prospects." Metrology 1, no. 1 (May 11, 2021): 17–38. http://dx.doi.org/10.3390/metrology1010002.

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In order to progress in the area of aeroacoustics, experimental measurements are necessary. Not only are they required for engineering applications in acoustics and noise engineering, but also they are necessary for developing models of acoustic phenomenon around us. One measurement of particular importance is acoustic impedance. Acoustic Impedance is the measure of opposition of acoustical flow due to the acoustic pressure. It indicates how much sound pressure is generated by the vibration of molecules of a particular acoustic medium at a given frequency and can be a characteristic of the medium.The aim of the present paper is to give a synthetic overview of the literature on impedance measurements and to discuss the advantage and disadvantage of each measurement technique. In this work, we investigate the three main categories of impedance measurement techniques, namely reverberation chamber techniques, impedance tube techniques, and far-field techniques. Theoretical principles for each technique are provided along with a discussion on historical development and recent advancements for each technique.
8

Wang, Zhen Jiang, and Feng Hua Lu. "The Acoustical Design of Conference Room Based on Speech Acoustic." Applied Mechanics and Materials 507 (January 2014): 127–30. http://dx.doi.org/10.4028/www.scientific.net/amm.507.127.

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Based on the the requirements of appropriate reverberation time for the speech acoustic-dominated conference room, which are stipulated in Code for architectural acoustical design of theater ,cinema and multi-use auditorium(GB/T 50356-2005), this paper is trying to redesign the conference room on the fifth floor of the college of architecture and civil engineering of Taiyuan University of Technology, on account of the problems found after the experimental measurement. And the author introduces Ecotect to simulate the redesigning plan, in the hope of providing reference to acoustical design for the speech acoustic-dominated conference room.
9

Autio, Hanna, Mathias Barbagallo, Carolina Ask, Delphine Bard Hagberg, Eva Lindqvist Sandgren, and Karin Strinnholm Lagergren. "Historically Based Room Acoustic Analysis and Auralization of a Church in the 1470s." Applied Sciences 11, no. 4 (February 10, 2021): 1586. http://dx.doi.org/10.3390/app11041586.

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Worship space acoustics have been established as an important part of a nation’s cultural heritage and area of acoustic research, but more research is needed regarding the region of northern Europe. This paper describes the historical acoustics of an important abbey church in Sweden in the 1470s. A digital historical reconstruction is developed. Liturgical material specific to this location is recorded and auralized within the digital reconstruction, and a room acoustic analysis is performed. The analysis is guided by liturgical practices in the church and the monastic order connected to it. It is found that the historical sound field in the church is characterized by the existence of two distinct acoustical subspaces within it, each corresponding to a location dedicated to the daily services of the monastical congregations. The subspaces show significantly better acoustic conditions for liturgical activities compared to the nave, which is very reverberant under the conditions of daily services. Acoustic transmission from the two subspaces is limited, indicating that the monastic congregations were visually and acoustically separated from the visitors in the nave and each other.
10

Prives, Leslie. "Good Vibrations: Schnitta Tackling Acoustical Engineering." IEEE Women in Engineering Magazine 8, no. 2 (December 2014): 35–37. http://dx.doi.org/10.1109/mwie.2014.2353294.

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11

Brandão, Eric, William D'Andrea Fonseca, and Paulo Henrique Mareze. "An algorithmic approach to electroacoustical analogies." Journal of the Acoustical Society of America 152, no. 1 (July 2022): 667–78. http://dx.doi.org/10.1121/10.0012886.

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The low-frequency behavior of acoustical transducers can be simulated with the so-called electroacoustical analogies (or lumped parameters). The main idea is that visual inspection of the transducer allows the derivation of an electroacoustic circuit that can be analyzed. The technique is computationally efficient and provides significant physical insight into the transducer. Electroacoustical analogies are taught today in many courses around the world. However, it is difficult to find reading material with an algorithmic approach to derive the electroacoustic circuit from the visual inspection of the transducer. This paper presents algorithms to derive the mechanical and acoustical circuits of transducer systems and how to couple the electrical, mechanical, and acoustical circuits for electrodynamic and capacitive transducers. A number of examples of the derivation are presented in detail. These techniques were conceived from an extensive search of the classical literature in acoustics and adapted to the teaching needs of undergraduate and graduate students of the Acoustical Engineering at the Federal University of Santa Maria in Brazil.
12

Wu, Jiu Hui, Boris Luk’yanchuk, Hua Ling Chen, and Ai Qun Liu. "Light-Driven Acoustic Band Gap Based on Metal Nanospheres." Advanced Materials Research 74 (June 2009): 17–20. http://dx.doi.org/10.4028/www.scientific.net/amr.74.17.

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In this paper, light-driven acoustic band gap is presented by considering two metal nanospheres illuminated simultaneously by laser and acoustic waves. The interaction between the photonics and phonons is investigated through optical distribution force, van der Waals distribution force, and acoustic pressure upon these nanospheres. Based on the optical force and van der Waals force, the acoustic form functions for the metal nanoaggregates with different optical intensity are calculated, and the light-driven acoustics band gap at low frequency band has been found. It is shown that the band gap width can be widened with increasing the incident laser intensity, or by using proper metal materials and background media. This could provide potential applications in optical nanoswitches and acoustical filters.
13

Golden, Matthew, Ethan Bourdeau, Jeffrey Fullerton, Herb Singleton, Karl Peterman, and Andrew Barnard. "Overview of technical certificate program from the Institute of Noise Control Engineering." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A66. http://dx.doi.org/10.1121/10.0015564.

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Standards are often misunderstood by even the most seasoned of acoustic professionals, let alone new technicians and engineers in the field, as they are often very complicated, written in piecemeal fashion by committees and are updated often. Some of the standards even conflict with one another. To help alleviate this problem, the Institute of Noise Control Engineering (INCE) is developing two technical certificate programs designed to educate and evaluate participants on the details of common standards used in the noise control industry. Each program will contain education, testing, and continuing education on ASTM International and Acoustics Society of America (ASA) standards. The first program will cover general acoustical measurements and environmental noise measurements. The second program will cover field testing of building acoustics, including airborne and impact noise insulation as described in ASTM E336, ASTM E1007, and associated standards. The courses are currently being developed with a target launch date of early 2023. Comparisons to similar programs that have been developed in other countries will be included. A business case will be made on how these programs will save noise control engineering firms time and money in training new staff.
14

Liu, Xu, Xiao Qin Liu, and Chang Liu. "Development of Near-Field Acoustical Holograph and its Review." Advanced Materials Research 971-973 (June 2014): 1598–601. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.1598.

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Near-field acoustic holography (NAH) is a powerful technique for identifying noise sources and visualizing acoustic field.The theory and algorithm of NAH techniques are introduced , and it is proved by experiment and simulation. The researches on near field acoustical holography (NAH) are reviewed,including the sound field separation technique and Patch NAH technique arisen in recent years.The difficulties in NAH and research on current situations are discussed , Finally,some engineering applications are introduced by detailed examples.
15

Lindberg, Jan, and Mark Moffett. "Acoustical Society of America Silver Medal in Engineering Acoustics: John L. Butler." Journal of the Acoustical Society of America 138, no. 3 (September 2015): 1861–64. http://dx.doi.org/10.1121/1.4934192.

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16

Zagrai, Nickolay, and Vladislav Zakharevitch. "Integration discipline acoustical engineering for training specialists in acoustics and close areas." Journal of the Acoustical Society of America 117, no. 4 (April 2005): 2390. http://dx.doi.org/10.1121/1.4785813.

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17

Kumar, Sanjay, and Heow Pueh Lee. "Recent Advances in Acoustic Metamaterials for Simultaneous Sound Attenuation and Air Ventilation Performances." Crystals 10, no. 8 (August 7, 2020): 686. http://dx.doi.org/10.3390/cryst10080686.

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In the past two decades, acoustic metamaterials have garnered much attention owing to their unique functional characteristics, which are difficult to find in naturally available materials. The acoustic metamaterials have demonstrated excellent acoustical characteristics that paved a new pathway for researchers to develop effective solutions for a wide variety of multifunctional applications, such as low-frequency sound attenuation, sound wave manipulation, energy harvesting, acoustic focusing, acoustic cloaking, biomedical acoustics, and topological acoustics. This review provides an update on the acoustic metamaterials’ recent progress for simultaneous sound attenuation and air ventilation performances. Several variants of acoustic metamaterials, such as locally resonant structures, space-coiling, holey and labyrinthine metamaterials, and Fano resonant materials, are discussed briefly. Finally, the current challenges and future outlook in this emerging field are discussed as well.
18

Paul, Stephan, Andrey R. da Silva, Erasmo F. Vergara, and Dinara X. da Paixão. "Brazil’s first undergraduate course in acoustical engineering." Journal of the Acoustical Society of America 128, no. 4 (October 2010): 2308. http://dx.doi.org/10.1121/1.3508121.

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19

Surez, E. "A successful undergraduate program in acoustical engineering." Journal of the Acoustical Society of America 128, no. 4 (October 2010): 2342. http://dx.doi.org/10.1121/1.3508291.

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20

Cho, Yong Thung, M. J. Roan, and J. S. Bolton. "A comparison of near-field beamforming and acoustical holography for sound source visualization." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, no. 4 (January 16, 2009): 819–34. http://dx.doi.org/10.1243/09544062jmes1209.

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Acoustical holography procedures make high-resolution visualization possible via estimation of the sound intensity on surfaces closer to the sources than the near-field measurement surface. Another source localization technique, beamforming, has been used to estimate the direction of arrival of sound from sources that typically lie in the far-field. However, little work has been done using beamforming as a visualization technique based on near-field measurements. As a result, the performance of beamforming and acoustical holography in terms of source resolution capabilities has not been directly compared when using near-field measurements. In this work, point source beamforming was used to visualize sources based on near-field measurements. Acoustic intensity estimated from beamformed pressure measurements was compared with the absolute intensity estimated using acoustical holography techniques. In addition to noise-free, anechoic simulations, cases of measurement pressure with random noise were generated and used to compare source resolution accuracy of acoustical holography and beamforming techniques in the presence of measurement noise. It was found that intensity estimated using acoustical holography provided the clearest image of sources when the measurement surface was conformal with the source geometry. However, sources can be resolved more accurately using near-field beamforming than acoustical holography at high frequencies when the sources are not located perfectly on a surface conformal with the measurement geometry.
21

Torres, Julio Cesar Boscher. "Acoustical Evaluation of the Itacuruçá Baptist Evangelical Church." International Journal of Architectural Engineering Technology 9 (December 28, 2022): 109–24. http://dx.doi.org/10.15377/2409-9821.2022.09.8.

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This paper presents the acoustical evaluation of a representative evangelical church in Rio de Janeiro, Brazil. The analysis, performed through measurements and simulations, has shown that the acoustic field needs to be more appropriate for the temple’s actual use. The analysis measured the impulse responses at 14 positions from 2 source locations and calculated Reverberation Time and Clarity Factor acoustic parameters. According to the literature and the ISO standards, the Reverberation Time was considered higher than the optimum value for both speech or music. An acoustic model for the temple was developed using the BRASS simulator. The simulation results were compared to measured data to validate the acoustic model. Based on that and aiming to achieve optimum acoustic parameters, a new model was proposed to evaluate alternatives to adequate the acoustical characteristics of the temple. The strategy to develop the final model and to achieve the target Reverberation Time is presented and discussed. An acoustic intervention is then proposed and evaluated using simulated data. The results obtained with the proposed changes, which considered the inclusion of perforated panels and carpet in some walls, were adequate, providing Reverberation Time in accordance to the standards and significant improvement to Clarity for music and speech.
22

Rindel, Jens Holger. "A note on meaningful acoustical parameters for open-air theatres." Acta Acustica 7 (2023): 20. http://dx.doi.org/10.1051/aacus/2023015.

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The acoustics of performance spaces are usually characterized by the reverberation time and a handful of other acoustical parameters defined in ISO 3382-1. However, these parameters have been derived with closed spaces in mind, and it is not obvious that the same parameters are meaningful in an open-air theatre. The lack of late reflections means that the decay curve is often far from a straight line, and the reverberation parameters turn out to be unreliable. Also, parameters that use the balance between early and late reflections are problematic when late reflections are more or less absent. It is necessary to rethink the need for acoustical parameters instead of sticking to the well-established parameters meant for concert halls. The most important acoustical features of a theatre are that speech is sufficiently loud and clear, which can be described by acoustical parameters for strength and clarity. In addition, it is important to avoid echoes, which are more likely to appear in an outdoor environment than in a room. Thus, there is a need for an objective echo parameter. Acoustical parameters that vary strongly with receiver position are not well suited for a global characterization of the acoustics of a space. For this purpose, a parameter for the acoustical efficiency is suggested; it is defined as ten times the logarithm of the total sound energy in the impulse response relative to the energy of the direct sound. The spatial average of this parameter can be used for comparison of the acoustics of different open-air theatres.
23

Wang, Lily M., Erica E. Ryherd, Joseph A. Turner, and Jinying Zhu. "Graduate studies in acoustics at the University of Nebraska – Lincoln within the College of Engineering." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A124. http://dx.doi.org/10.1121/10.0015758.

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Those interested in pursuing graduate studies and conducting research in acoustics are invited to learn more about opportunities at the University of Nebraska – Lincoln (UNL) within the College of Engineering. Dr. Lily Wang and Dr. Erica Ryherd work on architectural acoustics and noise control topics (http://nebraskaacousticsgroup.org ) within the Durham School of Architectural Engineering and Construction, based at UNL's Scott Campus in Omaha. Dr. Jinying Zhu in Civil and Environmental Engineering (also based on UNL’s Scott Campus in Omaha) is active in structural acoustics, using ultrasonic waves for concrete evaluation (https://engineering.unl.edu/cee/faculty/jinying-zhu/). Dr. Joseph Turner in Mechanical and Materials Engineering (based at UNL’s City Campus in Lincoln) focuses on ultrasound propagation through complex media for quantitative characterization of materials/microstructure (http://quisp.unl.edu ). This poster presents the graduate-level acoustics courses and lab facilities at UNL within the College of Engineering, and highlights the research interests and achievements of our faculty, graduates, and students. Extracurricular experiences are available through an Acoustical Society of America student chapter based on the Scott Campus and collaborations with Boys Town National Research Hospital.
24

Riccardi, Peter J., Zane T. Rusk, John A. Case, Heui Young Park, and Eric Rokni. "Penn State ASA student chapter educational workshops in engineering design tools for loudspeaker and amplifier system design." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A255. http://dx.doi.org/10.1121/10.0016191.

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Hands-on workshops and projects are an effective way to provide meaningful and memorable STEM education. To promote practical acoustics and engineering knowledge, the Pennsylvania State University Acoustical Society of America student chapter hosted a series of workshops wherein students learned the basics of electroacoustic transduction, mechanical modeling, electronics design, and PCB routing. This educational effort was accomplished by sponsoring a three-way loudspeaker design project. Transduction topics were covered by optimizing the model of a ported woofer in MathWorks SimScape, using the recently developed Acoustical Domain for Simscape available from MATLAB central. Mechanical modeling of the three-way speaker cabinets to produce manufacturing drawings was covered in SolidWorks workshops. Finally, the basics of circuit design, schematic capture, and PCB routing were covered in DipTrace through the design of a stereo integrated amplifier with an active crossover that was built to power the loudspeaker. Details about the workshops and performance of the designed components will be presented.
25

Dlhý, Dušan. "The Effect of Free Joints on Sound Insulation of Constructions." Advanced Materials Research 855 (December 2013): 233–36. http://dx.doi.org/10.4028/www.scientific.net/amr.855.233.

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Noise protection of a building ́s interior is one of the fundamental functions of building constructions. These constructions can be understood as internal partitions, ceilings or external wall-/roof claddings. However, walls often consist of basic building materials and openings; such windows and doors as well as the acoustical properties of such structures are determined by both parts (e.g., a windows and the wall structure). The acoustical quality of opening is in general affected not only by the particular structure, but also by the concept of the mounting. Acoustical requirements should be applied in all its parts, such as the construction of the window (door) frame, window (door) wing and the realization of the functional gap as well as by application of a sealant. On the base of experimental measurements in Acoustics Chambers of the Faculty of Civil Engineering of Slovak Technical University and mathematical analysis we have determined index of sound insulation of free joint.
26

Carvalho, António P. O., António E. J. Morgado, and Luís Henrique. "Relationships between Subjective and Objective Acoustical Measures in Churches." Building Acoustics 4, no. 1 (March 1997): 1–20. http://dx.doi.org/10.1177/1351010x9700400101.

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This study reports on subjective and objective acoustical field measurements made in a survey of 36 Catholic churches in Portugal built in the last 14 centuries. Monaural acoustical measurements (RT, EDT. C80, D50, TS and L) were taken at several source/receiver locations in each church and a group of college students was asked to judge the subjective quality of music. The listeners in each church evaluated live music performances at similar locations in each room. Evaluation sheets were used to record the listeners' overall impressions of room acoustic quality and also Loudness, Reverberance. Intimacy. Envelopment. Directionality, Balance, Clarity, Echoes and Background Noise. This paper concentrates on the relationships of the subjective parameters with the objective room acoustics measures and with the architectural features of the churches. Correlation analyses and statistical modeling identified significant relationships among the measures. For instance, linear correlation coefficients (| R|) of 0.8–0.9 were found for the relationships: Reverberance/RT and Clarity/C80; the maximum | R| found was 0.93 for Echoes/RT. Regarding architectural features the maximum | R | found was 0.87 between Intimacy and Total Volume.
27

Kienemund, Daniel, Nicole Bohn, Thomas Fink, Mike Abrecht, Walter Bigler, Joachim R. Binder, Rolf Jakoby, and Holger Maune. "Design and demonstration of acoustically optimized, fully-printed, BST MIM varactors for high power matching circuits." International Journal of Microwave and Wireless Technologies 10, no. 5-6 (April 17, 2018): 620–26. http://dx.doi.org/10.1017/s1759078718000387.

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AbstractThis work addresses the piezoelectric induced reduction of quality factor in fully-printed metal-insulator-metal (MIM) barium strontium titanate (BST) thick film varactors designed for high power operation. An acoustically optimized varactor design is presented and compared to a non-optimized high-power varactor. The design is utilized to present a narrowband acoustic suppression technique based on defined weights. The acoustically optimized varactor consists of 162 varactor cells in a capacitive matrix. The cells in the matrix are interconnectable allowing for a variable unbiased capacitance and power rating. Due to this setup, surface acoustic waves are interrupted, and the reduced size of the cells allows for a reduced BST layer thickness, shifting the acoustic resonance away from the operational frequency. Therefore, an inverted behavior in comparison to the high-power varactor is observed with an increasing quality factor with biasing voltage. Compared to the high-power varactor, the acoustically optimized varactor design shows a 40% increased quality factor in biased state. By applying the narrowband acoustic suppression technique, an increase in quality factor of 145% is achieved compared to the unsuppressed design. In comparison to the high-power varactor, the acoustical suppressed design shows an increase in quality factor of 480% at the first acoustic resonance frequency.
28

Campbell, Richard H., and Frederick W. Bianchi. "The virtual orchestra; acoustical and audio engineering issues." Journal of the Acoustical Society of America 103, no. 5 (May 1998): 2824. http://dx.doi.org/10.1121/1.421926.

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29

Razavi, Zohreh. "Requirement of acoustical engineering discipline in building designs." Journal of the Acoustical Society of America 144, no. 3 (September 2018): 1740. http://dx.doi.org/10.1121/1.5067716.

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30

Myers, Arnold. "The acoustical engineering of brasswind instruments 1779–1929." Journal of the Acoustical Society of America 115, no. 5 (May 2004): 2565. http://dx.doi.org/10.1121/1.4809271.

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31

Jasinski, Christopher M., and Robert Celmer. "A Capstone Acoustical Engineering Design course with industry-sponsored projects." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A114. http://dx.doi.org/10.1121/10.0010824.

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One of the transitions that engineering students must make as they enter the work force is the progression from theoretical concepts to applied/real world applications. At the University of Hartford, engineering design courses serve as culminating experiences devised to bridge this passage. One such course, Acoustics Capstone Design, challenges the student to apply the past three years' conceptual base of two acoustics and two vibration courses to a problem-solving opportunity replete with actual scenarios encountered in industry. Each year local firms approach our Engineering Applications Center for assistance with a variety of sound or vibration problems. After an initial training period, students make use of the laboratory's FFT/real time analyzers, anechoic/reverberation chambers, sound intensity and modal analysis software, acoustic modeling software, and vibration shaker/transducers. Using a consultant-client model, students work collaboratively in teams of two defining the problem, developing a method of approach, making appropriate measurements, devising alternate solutions, and ultimately delivering a written and oral presentation at the end of the semester. The arrangement regularly results in employment offers for the graduating seniors. The paper discusses specific projects and some experiences students have had with their first industrial assignment, as well as creative means of equipment acquisition.
32

Grelowska, Grażyna, and Eugeniusz Kozaczka. "Underwater Acoustic Imaging of the Sea." Archives of Acoustics 39, no. 4 (March 1, 2015): 439–52. http://dx.doi.org/10.2478/aoa-2014-0048.

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Abstract Acoustic waves are a carrier of information mainly in environments where the use of other types of waves, for example electromagnetic waves, is limited. The term acoustical imaging is widely used in the ultrasonic engineering to imaging areas in which the acoustic waves propagate. In particular, ultrasound is widely used in the visualization of human organs-ultrasonography (Nowicki, 2010). Expanding the concept, acoustical imaging can also be used to presentation (monitoring) the current state of sound intensity distribution leading to characterization of sources in observed underwater region. This can be represented in the form of an acoustic characteristic of the area, for example as a spectrogram. Knowledge of the underwater world which is built by analogy to the perception of the space on the Earth's surface is to be systematize in the form of images. Those images arise as a result of graphical representation of processed acoustic signals. In this paper, it is explained why acoustic waves are used in underwater imaging. Furthermore, the passive and active systems for underwater observation are presented. The paper is illustrated by acoustic images, most of them originated from our own investigation.
33

Schomer, Paul D. "ACOUSTICAL SOCIETY OF AMERICA Silver Medal in Noise 2021: Paul D. Schomer." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A193—A196. http://dx.doi.org/10.1121/10.0009988.

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The Silver Medal is presented to individuals, without age limitation, for contributions to the advancement of science, engineering, or human welfare through the application of acoustic principles, or through research accomplishment in acoustics.
34

Jasinski, Christopher M., and Robert D. Celmer. "Effective educational practices, assessment, and applications in acoustics and vibration at the University of Hartford." Journal of the Acoustical Society of America 152, no. 1 (July 2022): 633–39. http://dx.doi.org/10.1121/10.0012697.

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The University of Hartford is home to two unique undergraduate engineering majors in acoustics, both sharing a core course layout of acoustics, vibrations, and projects. The Bachelor of Science in Mechanical Engineering with an Acoustics Concentration and the Bachelor of Science in Engineering in Acoustical Engineering and Music programs allow for two complementary tracks within the acoustics field, providing cohesive plans of study on many facets of listening and design. All Mechanical Engineering majors (regardless of concentration) are required to take Vibrations I and a course in Engineering and Environmental Acoustics. The department philosophy for this inclusion is that acoustics and vibration design considerations are an essential component for the development of the complete mechanical engineer. This paper outlines program educational goals and outcomes, along with pedagogical adjustments made based on continuous assessment and evaluation of select courses, including recent changes to adapt to measured deficiencies. The paper also details the historical development of the acoustics program, components of the Vibrations I and Engineering & Environmental Acoustics courses, and example research and design projects based on work in these courses. Among the included projects are modal analysis, community room acoustics assessment, and an open access computational room acoustics simulator for use and collaboration with colleagues in acoustics education.
35

Graham, Megan E. "Long-term care as contested acoustical space: Exploring resident relationships and identities in sound." Building Acoustics 27, no. 1 (December 8, 2019): 61–73. http://dx.doi.org/10.1177/1351010x19890478.

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As the global population ages, residential care facilities are challenged to create positive living environments for people in later life. Health care acoustics are increasingly recognized as a key design factor in the experience of well-being for long-term care residents; however, acoustics are being conceptualized predominantly within the medical model. Just as the modern hospital battles disease with technology, sterility and efficiency, health care acoustics are receiving similar treatment. Materialist efforts towards acoustical separation evoke images of containment, quarantine and control, as if sound was something to be isolated. Sound becomes part of the contested space of long-term care that exists in tension between hospital and home. The move towards acoustical separation denies the social significance of sound in residents’ lives. Sound does not displace care; it emplaces care and the social relationships therein. Drawing upon ethnographic fieldwork in a Canadian long-term care facility, this article will use a phenomenological lens to explore how relationships are shaped in sound among residents living in long-term care. Ethnographic vignettes illustrate how the free flow of music through the care unit incited collective engagement among residents, reduced barriers to sharing social space and constructed new social identity. The article concludes that residents’ relationships are shaped within the acoustical milieu of the care unit and that to impose acoustical separation between residents’ living spaces may further isolate residents who are already at risk of loneliness.
36

Xu, Yi Feng, and Jun Wang. "Modal Parameter Validation in Coupled Vibro-Acoustical System." Advanced Materials Research 301-303 (July 2011): 629–34. http://dx.doi.org/10.4028/www.scientific.net/amr.301-303.629.

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The aim of this paper is to validate the modal parameters used in coupled structural finite element and acoustic boundary element algorithm to analysis the structure subjected to diffuse acoustic field. The theoretical deduction of non-symmetric coupled vibro-acoustical modal analysis was introduced firstly. In order to verify the modal truncation frequency how to affect the simulation results, based on the reciprocity theorem used in coupled FE-BE model, three different truncation frequency conditions were performed. The contrastive results show that twice the upper calculation frequency as the truncated modal frequency can make the simulation effectively and efficiently.
37

Rawlinson, R. D. "Acoustic Design of Lightweight Gas Turbine Enclosures." Journal of Engineering for Gas Turbines and Power 113, no. 4 (October 1, 1991): 544–49. http://dx.doi.org/10.1115/1.2906275.

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Acoustic enclosures for the gas turbine industry have to comply with a number of stringent safety requirements including structural strength, fire resistance, and sound insulation. This has led traditionally to heavy enclosure designs. Corrugated enclosure panels offer significant structural advantages because of their increased bending stiffness. Consequently, a corrugated panel of a given thickness can give the same structural strength as a flat panel of substantially greater weight and thickness. However, corrugated panels are intrinsically less effective as a sound insulator than flat panels of the same thickness. This paper examines the implications of corrugated, lightweight panels for acoustic enclosures. It illustrated that, by careful design, the inherent acoustical disadvantages of corrugated panels can be overcome so that thinner, lighter, and more cost-effective enclosures can be used without compromising the overall structural and acoustical design requirements.
38

Tang, Xiaoning, Xiansheng Zhang, Xingmin Zhuang, Huiping Zhang, and Xiong Yan. "Acoustical analysis of corduroy fabric for sound absorption: Experiments and simulations." Journal of Industrial Textiles 48, no. 1 (August 7, 2017): 201–20. http://dx.doi.org/10.1177/1528083717725912.

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Corduroy fabrics have been widely used in interior decoration currently. This work mainly investigated the acoustical properties of corduroy fabrics in relation to air permeability and airflow resistance. Five specimens with similar surface density and different wale width are used. The results indicated that corduroy fabrics with thicker wale width exhibited higher air permeability and lower airflow resistance. Furthermore, the increased width of wale is beneficial to improve the acoustic absorption of corduroy fabric. Two models based on air permeability and airflow resistance are taken to characterize the acoustical behavior. It has been indicated that Pieren model could well predict the acoustic absorption coefficient of corduroy fabric, and the difference of acoustic absorption is due to the varied air permeability and airflow resistance resulting from the different wale width.
39

Beranek, Leo L. "The Acoustical Design of Concert Halls." Building Acoustics 1, no. 1 (March 1994): 3–25. http://dx.doi.org/10.1177/1351010x9400100102.

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A brief account is given of the early history of room acoustics and in particular W.C. Sabine's discovery of the importance of reverberation time on the acoustical quality of a room. There follows an account of later work, including that of the author, in which five other parameters, i.e. initial time delay, loudness, diffusion, spatial impression and early to late energy ratio, were identified as contributing to acoustical quality. The acoustical design of a number of halls after 1950 is discussed and an account is given of the history of the design of the Philharmonic Hall in the Lincoln Center up to the present time. Some attempts made by architects to break away from the safe shoe-boxed shape of hall are described and the acoustical consequences discussed. The success of four recently designed halls is shown to be the direct result of lessons learned both from experience in real halls and the fundamental research work mentioned in this paper. Finally, a brief account is given of the objective parameters that can now be measured in halls and which relate to subjective response.
40

T., Pazara. "Sound propagation modelling in a lecture hall." Scientific Bulletin of Naval Academy XXII, no. 2 (December 15, 2019): 276–83. http://dx.doi.org/10.21279/1454-864x-19-i2-033.

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For lecture halls, intelligibility of speech is the most important aspect. To achieve a relative uniform distribution of sound among the listeners, a number of parameters must be taken into account. One method to speed up the design process of a lecture hall is to model the sound propagation in that room using computer acoustic software. In this paper, the authors have chosen a lecture hall from Naval Academy and made numerous simulations to discover what are the week points regarding the acoustics of this room. The acoustical parameters obtained from simulations are compared with the desired ones and a few remarks for the improvement of the room are made.
41

Watanabe, Takayuki, and Masahiro Ikeda. "Improvement of the Acoustics under the Balcony in Auditoria Using the Electro-Acoustic Method—A Study with a Full-Scale Model." Building Acoustics 18, no. 3-4 (December 2011): 281–92. http://dx.doi.org/10.1260/1351-010x.18.3-4.281.

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In auditoria, the acoustical properties of audience areas located under balconies are regarded as inferior to the main area. This is caused by the reduction of direct and reflected sound energy due to the smaller open area and the reduction of diffusive energy due to the limited acoustical space. In this paper, a new electro-acoustic system is proposed to compensate for this acoustical condition. The proposed system is a non-regenerative system and consists of directional microphones, head amps, a convolver, a matrix processor, amplifiers, and ceiling loudspeakers located under the balcony. The loudspeakers, located at positions corresponding to measurement points across the balcony, recreate the reflecting sound from above the balcony area, which otherwise fail to reach to the listeners under the balcony. The authors have examined the proposed system's performance via two methods: acoustical measurement using a full-scale model and a corresponding psycho-acoustical experiment. The results showed that the energy of the reflections from above the system was the same or more than that without the balcony, and the decay curve with the system was almost the same as that without the balcony. The MUSHRA method was used in the psycho-acoustical experiment, which focused on the evaluation of apparent source width (ASW) and listener envelopment (LEV). The results of the experiment show that the system is significantly better for all tests to the use of no system and that the system is superior to a standerd PA (delay system).
42

Park, Chan-Jae, and Chan-Hoon Haan. "Initial Study on the Reverberation Time Standard for the Korean Middle and High School Classrooms Using Speech Intelligibility Tests." Buildings 11, no. 8 (August 15, 2021): 354. http://dx.doi.org/10.3390/buildings11080354.

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The most important function of the classroom is to transmit educational information from teachers to students more accurately and clearly. The acoustical environment of the classroom thus has an important effect on the improvement of students’ learning ability. To provide an appropriate acoustical environment for learning to students, it is necessary to create an acoustical performance standard for classrooms and a guideline for designing classrooms. However, in Korea, there is not an acoustical standard for classrooms; thus, it is difficult to control and manage appropriate acoustical performance when designing and building classrooms. The present study aims to suggest acoustic performance standards for classrooms that are suitable for the Korean language. In order to perform this study, standard classrooms were created by standardizing architectural dimensions of 17 middle and high school classrooms in Cheong-ju. Speech intelligibility tests were conducted using three different languages including Korean, English, and Chinese. Twenty native speakers for each language were used as subjects for the speech intelligibility tests. Finally, auralized sound sources were created with five different conditions of reverberation time (0.47~1.22 s) by changing indoor sound absorption of a real classroom. Listening tests were undertaken by 52 Korean adults with normal hearing, using the auralized sound source. The results proved that the most appropriate reverberation time for learning was above 0.76 s. Based on the research findings, the ideal acoustical performance standard for classrooms in Korea is as follows: background noise is below 35 dBA, and reverberation time is below 0.80 s. It is also necessary that indoor sound absorption should be above 20% without sound absorption on side walls in order to satisfy with the acoustical performance standard.
43

Bansod, Pritesh V., and Amiya R. Mohanty. "Inverse estimation of the Dunn and Davern model coefficients for jute material using the particle swarm optimization method." Textile Research Journal 87, no. 17 (September 13, 2016): 2166–75. http://dx.doi.org/10.1177/0040517516665264.

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Today many different natural materials are being effectively used in the acoustics and noise control domain. In this study, the acoustical characterization of three different types of natural jute felt material is performed by an experimental method and by using the Dunn and Davern model, along with an inverse characterization method. There are many empirical models available in the literature which describes the acoustical behavior of specific material accurately, as they are specially developed for that material. In this study, the possibility of using only the air flow resistivity based Delany–Bazley model and the Dunn–Davern model for acoustical performance prediction of jute material is tested. However, these two models do not show good matching with the experimental data throughout the frequency range of interest. Particularly in the low frequency region, the level of mismatch between experimental and model data is high. Therefore the inverse prediction of the coefficients [Formula: see text] in Dunn–Davern model using the particle swarm optimization (PSO) method is conducted, and new coefficients for jute material are found. These new coefficients better predict the acoustical performance of jute felts and reduce the mismatch level in the low-frequency region.
44

Thilmany, Jean. "The Quiet Forefront." Mechanical Engineering 136, no. 08 (August 1, 2014): 44–49. http://dx.doi.org/10.1115/8.2014-aug-3.

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This article highlights the acoustical analysis changes made by manufacturers in design cycle. Acoustical simulation is being pushed from experts to designers, following the trend for the last 15 or so years that saw other types of engineering applications like finite element analysis and computational fluid dynamics become integrated with computer-aided design packages used by mechanical engineers. With the advent of software packages that allow for design and for acoustical analysis in tandem, design engineers are increasingly running these analyses early in the development cycle and are making design changes to decrease noise and vibration issues they find. Experts suggest that with speaker sound quality and other pertinent information in hand, designers can actually design from the get-go with that information in mind, resulting in fewer design changes down the line. Though early acoustical simulation is still perhaps one of the consumer electronics’ industries best-kept secrets, that’s likely to change as word gets out about the many advantages of front-line simulation.
45

Le Moyne, S., J. L. Tebec, and I. Tawfiq. "Acoustical influence of stiffeners on acoustic radiation of plates." Mechanical Systems and Signal Processing 19, no. 1 (January 2005): 195–212. http://dx.doi.org/10.1016/s0888-3270(03)00054-2.

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46

Ramezanpour, Reza, and Yangfan Liu. "An equivalent source method for holographic visualization of acoustic sources in an apertured enclosure based on exterior measurements." Journal of the Acoustical Society of America 153, no. 3_supplement (March 1, 2023): A56. http://dx.doi.org/10.1121/10.0018145.

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Most acoustical holography techniques are developed to visualize sound sources or reconstruct sound field in a free-space environment, where no boundary reflected or scattered sound are present. However, in some engineering applications, a sound scatter is an inseparable part of source mechanism. For example, for a centrifugal fan, the aerodynamic noise sources are the turbulent pressure inside the fan shell, but the source distribution is significantly altered if the fan shell is removed. Thus, in order to visualize the sources inside the fan shell by holography methods based on exterior sound measurements, the measurements need to be performed with the presence of the shell (which is a sound scatter). This obviously violates the free-space assumption for most acoustical holography methods. In this work, traditional free-space equivalent source methods are extended to visualize acoustic sources situated in an enclosure with openings based on sound measurements exterior to the enclosure. The key step is to replace the free-space Green’s function used in traditional equivalent source methods by a Green’s function that satisfies the boundary condition of the apertured enclosure. Simulations are performed to prove the concept of the proposed acoustical holography method.
47

Kaselouris, Evaggelos, Chrysoula Alexandraki, Yannis Orphanos, Makis Bakarezos, Michael Tatarakis, Nektarios A. Papadogiannis, and Vasilis Dimitriou. "Acoustic analysis of impact sound on vibrating circular membranes." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 3 (August 1, 2021): 3378–85. http://dx.doi.org/10.3397/in-2021-2389.

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A finite element method (FEM) - boundary element method (BEM) model is developed to compute the sound generated by of a force acting on a circular membrane (drumhead). A vibro-acoustic analysis that combines modal FEM analysis, a FEM steady state dynamic analysis (SSD), considering harmonic loading and boundary element acoustics, is performed. The drumhead vibrates due to the force impact and the sound is emitted in the air. The vibration of structural response is initially computed, and the obtained results are set to be the boundary conditions of the acoustic analysis in the vibro-acoustic simulation. The radiated sound can be computed at any point of the solution domain. Various materials used by drumhead manufacturers are tested and a parametric analysis focusing on the mesh density of the models is presented. The impact sound and the acoustical characteristics of the simulated test cases are evaluated. The Rayleigh method is also applied to the acoustic simulations and is further compared to the BEM simulation results. The outcomes of this study may be further used as reverse engineering inputs, to machine learning models for the estimation of the physical and mechanical parameters of drumheads from audio signals.
48

Celmer, Robert D., and Michelle C. Vigeant. "Undergraduate acoustical engineering programs at the University of Hartford." Journal of the Acoustical Society of America 126, no. 4 (2009): 2227. http://dx.doi.org/10.1121/1.3248958.

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49

Xue, W. F., J. Chen, J. Q. Li, and X. F. Liu. "Acoustical feature extraction of rotating machinery with combined wave superposition and blind source separation." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 220, no. 9 (September 1, 2006): 1423–31. http://dx.doi.org/10.1243/0954406jmes189.

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As the result of vibration emission in air, machine sound signal carries affluent information about the working condition of machine and it can be used to make mechanical fault diagnosis. The fundamental problems with fault diagnosis are the estimation of the number of sound sources and the localization of sound sources. The wave superposition can be employed to identify and locate sound sources, which is based on the idea that an acoustic radiator can be approximated and represented by the sum of the fields due to a finite number of interior point sources. But, in practice, a large number of measurements must be used in order to achieve a desired resolution, which makes the reconstruction process very time-consuming and expensive. In this paper, a combined wave superposition method has been developed reconstruct to acoustic radiation from machine acoustical signals. This method combines the advantages of both the wave superposition and Helmholtz equationleast squares methods, and it allows for reconstruction of the acoustic field from an arbitrary object with relatively few measurements, thus significantly enhancing the reconstruction efficiency. After sound source localization, the blind source separation (BSS) is proposed to extract acoustical feature from the mixed measuring sound signals. In a semi-anechoic chamber, a cross-planar microphone array, which consists of 29 microphones, was successfully applied to obtain the two-dimensional mapping of the sound sources. The location, the sound pressure, and the properties in frequency domain of the sound sources can be found through this method precisely. The experimental results demonstrate that the methods presented can potentially become an acoustical diagnosis tool.
50

Vargová, Andrea, and Monika Pavčeková. "Noise Perception in Residential Building Environment." Advanced Materials Research 649 (January 2013): 281–84. http://dx.doi.org/10.4028/www.scientific.net/amr.649.281.

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This article brings up to discussion a particularly topical issue which is the quality of sound insulation in Slovakian dwellings. An analysis of the current acoustical situation in newly built or renovated buildings is shown, as well as the importance of a subjective evaluation of acoustical comfort is highlighted. Nevertheless, it is known that the acoustical comfort is one of the most important factors of a healthy living environment and that the acoustical defects often become subject of argumentation. Concerning the growing acoustical problems in dwellings, we could debate, to what extent the real value of the apartment can be estimated.

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