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1
Tomiku, Reiji, Noriko Okamoto, Toru Otsuru, Shun Iwamoto, and Shoma Suzuki. "Finite element sound field analysis on measurement of absorption coefficient in a reverberation room -Relationships between inclination of walls and measurement results-." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 1 (August 1, 2021): 5571–77. http://dx.doi.org/10.3397/in-2021-3158.
Повний текст джерелаАнотація:
The absorption coefficients in a reverberation room are most representative measure for evaluating absorption performance of architectural materials. However, it is well known that measurement results of the coefficient vary according to a room shape of the measurement and area of the specimen. Numerical analyses based on wave acoustics are effective tools to investigate these factors on absorption coefficient measurement in reverberation room. In this study, sound fields for the measurement of absorption coefficient in reverberation room are analyzed by time domain finite element method (TDFEM). This study shows effectiveness of the analysis for investigation on causes of variation in the measurement results and improvement methods of the measurement. First, some measurement sound fields for absorption coefficient in reverberation rooms the walls of which are incline or decline are analyzed by the TDFEM. Next, reverberation times in each sound fields are calculated from the results obtained by TDFEM and the absorption coefficients are evaluated from the reverberation time of the room with and without specimen. Finally, the relationships among room shape, degree of inclination of the wall, the sound absorption coefficient of the specimen, frequencies and the measurement absorption coefficient are investigated.
2
Astolfi, Arianna, Elena Bo, Francesco Aletta, and Louena Shtrepi. "Measurements of Acoustical Parameters in the Ancient Open-Air Theatre of Tyndaris (Sicily, Italy)." Applied Sciences 10, no. 16 (August 15, 2020): 5680. http://dx.doi.org/10.3390/app10165680.
Повний текст джерелаАнотація:
The emerging field of archaeoacoustics is attracting increasing research attention from scholars of different disciplines: the investigation of the acoustic features of ancient open-air theatres is possibly one of its main themes. In this paper, the outcomes of a measurement campaign of acoustical parameters in accordance with ISO 3382-1 in the ancient theatre of Tyndaris (Sicily) are presented and compared with datasets from other sites. Two sound sources were used (firecrackers and dodecahedron) and their differences were analysed. A very good reproducibility has been shown between the two measurement chains, with differences on average of 0.01 s for reverberation time T20, and less than 0.3 dB for Clarity C50 and C80 and for sound strength. In general, results show that the reverberation time and strength of sound values are relatively low when compared with other theatres because of the lack of the original architectural element of the scaenae frons. When combining this effect with the obvious condition of an unroofed space, issues emerge in terms of applicability of the protocols recommended in the ISO standard. This raises the question of whether different room acoustics parameters should be used to characterise open-air ancient theatres.
3
Çakir, Onurcan, Zeynep Sevinç, and Mustafa Emre İlal. "Characterization of Noise in Eating Establishments Based on Psychoacoustic Parameters." Applied Mechanics and Materials 887 (January 2019): 539–46. http://dx.doi.org/10.4028/www.scientific.net/amm.887.539.
Повний текст джерелаАнотація:
Noise in eating establishments has been studied in architectural acoustics literature. For evaluating acoustics in these spaces, researchers predominantly investigate sound pressure levels and reverberation times. Yet, noise in eating spaces originate from a wide variety of sources and is hard to describe and evaluate with only sound pressure levels and reverberation times. Better metrics for acoustics in closed public spaces are needed. Psychoacoustic parameters of loudness, sharpness, fluctuation strength and roughness are promising metrics that have been used by many recent studies evaluating noise annoyance. However, unlike the established metrics such as reverberation time, no set of recommended values exist for these parameters, yet. The aim of this study is to investigate noise in eating establishments through psychoacoustic parameters and understand both the noise characteristics and the metrics themselves. This paper presents a set of sound recordings during lunch hours in two eating spaces in Izmir Institute of Technology. The entry and egress of occupants have been tracked manually, while sound levels have been measured and the noise has been recorded for psychoacoustics analysis. The relationship between the number of occupants and psychoacoustic parameters has been investigated through these objective measurements. The relationship between the number of occupants and sound levels is discussed in the light of the Lombard effect.
4
Syamsiyah, Nur Rahmawati, Atyanto Dharoko, Sentagi Sesotya Utami, and Afizah Ayob. "Sustainability Relationship Between Space Configuration, Activity Patterns, and Mosque Acoustics Quality." Journal of Islamic Architecture 7, no. 2 (December 22, 2022): 262–69. http://dx.doi.org/10.18860/jia.v7i2.15121.
Повний текст джерелаАнотація:
The Great Mosque of Yogyakarta was built in 1773. This mosque has a traditional architectural style. This study investigates the relationship between the mosque's architectural form, the activities inside it, and its acoustic characteristics. It employed quantitative and qualitative methods, including sound pressure level (SPL) measurement, reverberation time, and architectural and activity observations. Acoustic measurements, architectural observations, and activities are conducted inside and outside the mosque from morning to night for one week. The research finding is a spatial continuity pattern identified as the gradation of SPL value. Consistent continuity of SPL values in accordance with the nature of activities hierarchy. The result of this study is to improve mosque noise control by arranging outdoor and indoor spaces in a sustainable manner.
5
Đorđević, Zorana, Dragan Novković, and Uroš Andrić. "Archaeoacoustic Examination of Lazarica Church." Acoustics 1, no. 2 (May 17, 2019): 423–38. http://dx.doi.org/10.3390/acoustics1020024.
Повний текст джерелаАнотація:
The acoustic analysis provides additional information on building tradition and related indoor practice that includes sound, thus deepening our understanding of architectural heritage. In this paper, the sound field of the Orthodox medieval church Lazarica (Kruševac city, Serbia) is examined. Lazarica is a representative of Morava architectural style, developed in the final period of the Serbian medieval state, when also the chanting art thrived, proving the importance of the aural environment in Serbian churches. The church plan is a combination of a traditional inscribed cross and a triconch. After the in situ measurement of acoustic impulse response using EASERA software, we built a computer model in the acoustic simulation software EASE and calibrated it accordingly. Following the parameters (reverberation time (T30), early decay time (EDT) and speech transmission index (STI)), we examined the acoustic effect of the space occupancy, central dome and the iconostasis. In all the cases, no significant deviation between T30 and EDT parameter was observed, which indicates uniform sound energy decay. Closing the dome with a flat ceiling did not show any significant impact on T30, but it lowered speech intelligibility. The height of iconostasis showed no significant influence on the acoustics of Lazarica church.
6
Siebein, Gary W., Marylin Roa, Matthew Vetterick, and Jennifer Miller. "Acoustical criteria and design approaches for music education and rehearsal spaces." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A210. http://dx.doi.org/10.1121/10.0011070.
Повний текст джерелаАнотація:
Case studies of three music education spaces will present acoustical measurement data with architectural features of the rooms compared to criteria from Sabine (1964), Pirn (1978), Gade (1988), Wenger (2008), and Tsaih (2011) among others to assess the sound qualities of the spaces. Among other qualities, reverberation time, room volume, hearing each other, and speech intelligibility are evaluated. Data are also compered to the Norwegian Standard NS 8178-2014. The case studies show how these criteria can be achieved given very different architectural systems employed in the rooms and describe the limits of where the qualities cannot be achieved due to the limits of program, budget, site, or space. Efforts are made to make each surface in the rooms acoustically productive in an optimized design to the extent practicable.
7
Kurniasih, Sri. "ANALISIS WAKTU DENGUNG PADA GEDUNG BALAI SARBINI." Jurnal Penelitian dan Karya Ilmiah Arsitektur Usakti 16, no. 02 (December 12, 2018): 82. http://dx.doi.org/10.25105/agora.v16i02.3232.
Повний текст джерелаАнотація:
<p>Semakin berkembangnya dunia hiburan semakin banyaknya pembangunan gedung-gedung yang membutuhkan sistem akustik salah satunya adalah gedung Balai Sarbini yang berfungsi sebagai gedung pertunjukan. Terkadang perancang hanya memfokuskan pada tampilan fasade bangunannya saja tanpa memperhatikan kenyamanan pengguna bangunan baik dari segi kenyamanan termal, kenyamanan visual maupun kenyamanan suara. Hal inilah yang terkadang menimbulkan permasalahan terutama permasalahan akustik baik permasalahan pada penerima suara maupun permasalahan pada rancangan arsitekturnya. Dengan demikian perlu diketahui tingkat nilai waktu dengung yang terjadi pada gedung Balai Sarbini. Adapun tujuan dari penelitian ini adalah untuk meninjau dan menganalisis sistem akustik baik dari rancangan, penggunaan material maupun perhitungan <em>Reverberation Time</em> (RT) pada bangunan Balai Sarbini yang kemudian disesuaikan dengan tinjauan teori, persyaratan dan standar perhitungan akustik. Metode penelitian yang digunakan adalah deskriptif kuantitatif, berupa uraian yang didapat dari data primer yang ada di lapangan dan teori-teori dasar terkait dari beberapa literatur, yang kemudian melakukan pengukuran dan perhitungan waktu dengung Pertunjukan sebagai objek penelitian dimana hasil pengukuran dan perhitungan tersebut akan disesuaikan dengan standar waktu dengung. Hasil penelitian waktu dengung (RT) kondisi eksisting Gedung Balai Sarbini tanpa bantuan elektro akustik adalah 0,6 detik saat kosong penonton, dan 0,72 detik saat penonton penuh (1000 orang). Dengan demikian dapat dinyatakan bahwa kalkulasi waktu dengung/Reverberation Time (RT) untuk gedung Concert Hall, maka gedung Balai Sarbini kurang/belum memenuhi ketentuan umum.</p><p><em> </em></p><p><strong><em>Kata Kunci:</em></strong><em> </em><em>Akustik, gedung balai Sarbini, waktu dengung</em></p><p> </p><p align="center"><strong><em>ABSTRACT</em></strong></p><p align="center"><strong><em> </em></strong></p><p><em>The development world of entertainment the more the construction of buildings that require an acoustic system one of which is the Hall Sarbini that serves as a performance building. Sometimes the designer only focuses on building façade façade alone regardless of the comfort of the building user in terms of thermal comfort, visual comfort and sound comfort. This is what sometimes causes problems especially acoustic problems both the problems on the recipients of the sound and the problems in the design of the architecture. Thus it is necessary to know the level of the time value of the buzz that occurred at Balai Sarbini building. The purpose of this research is to review and analyze the acoustic system from design, material use and Reverberation Time (RT) calculation on Balai Sarbini Hall building which is then adjusted to theoretical review, requirement and standard of acoustic calculation. The research method used is descriptive quantitative, in the form of description obtained from the primary data in the field and related basic theories from several literatures, which then perform the measurement and calculation of the time drone Performance as the object of research where the results of measurements and calculations will be adjusted with standard time drone. The result of research of the buzzer (RT) condition of existing Balai Sarbini Hall without the aid of acoustic electro is 0,6 second when empty of audience, and 0,72 second when the audience is full (1000 people). Thus it can be stated that the calculation of Reverberation Time (RT) for the Concert Hall building, the Balai Sarbini building has not fulfilled the general requirement.</em></p><p><em> </em></p><p><strong><em>Keywords: </em></strong><em>Acoustics, Hall of Sarbini building, performances, buzzing time</em><em> </em><em></em></p>
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Nowoświat, Artur, and Marcelina Olechowska. "Experimental Validation of the Model of Reverberation Time Prediction in a Room." Buildings 12, no. 3 (March 13, 2022): 347. http://dx.doi.org/10.3390/buildings12030347.
Повний текст джерелаАнотація:
It is well known that the uncertainty of input data has a great influence on the accuracy of room acoustics simulations. The aforementioned accuracy is significantly influenced by the selection of the acoustic properties of room-delimiting materials. Moreover, simulation errors are attributed to the fact that rooms can be very irregular and sound diffusion can be uneven, and thus sound absorption can be unevenly distributed over the surfaces. Therefore, a very important element is the validation of the simulation model of interior acoustics, even when we use ready-made software dedicated to interior acoustics for the simulation. In the article, the reverberation room model simulated in the ODEON program was subjected to validation. The program is based on a hybrid method combining the ray and virtual source methods. For the validation, appropriate measurements of the reverberation time in that room were carried out. The validation was undertaken using the criterion of correct validation, consisting of comparing the value of the comparison error and the value of the validation uncertainty.
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Zhang, Shuying, and Joonhee Lee. "Diffuseness Quantification in a Reverberation Chamber and Its Variation with Fine-Resolution Measurements." Buildings 11, no. 11 (November 4, 2021): 519. http://dx.doi.org/10.3390/buildings11110519.
Повний текст джерелаАнотація:
Insufficient diffuseness is the major cause of the poor repeatability and reproducibility of building acoustical measurements in a reverberation chamber. Inaccurate results were reported for the prevailing methods in ISO and ASTM standards. Many previous studies, thus, have proposed new methods to quantify the diffuseness of a reverberation chamber more accurately, but there is no general agreement among researchers on the most reliable method. The number of measurement samples required for these diffuseness metrics is also unclear, even though it significantly impacts the robustness of the methods. This study, therefore, aims to compare the performance of the two widely used diffuseness metrics (spatial variation of sound pressure levels and the relative standard deviation of decay rates) in the standards and the recently introduced metric (degree of time series fluctuation). The measurements were carried out with fine resolution microphone positions and varied configurations of acoustic diffusers. The degree of time series fluctuation showed the best correlation with varying diffuser configurations in the low-frequency range. Confidence intervals and coefficients of variation of the three metrics by random sampling also indicated that DTF is more reliable for evaluating the diffuseness in a sound field as it is less influenced by the number of sampling.
10
Chen, Xiang Rong. "Basic Principle of Acoustics and Architectural Suggestions for the Auditorium in Theater." Advanced Materials Research 971-973 (June 2014): 2061–67. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.2061.
Повний текст джерелаАнотація:
Many new Grand Theaters are constructed around China in recent years, and it is very important for architect to be familiar with the basic principle and knowledge of acoustics when designing the theaters. RT (Reverberation Time), ITDG (Initial Time Delay Gap), Loudness, BR, Surrounded sense and spatial sense are the major factors that affect the sound quality of the hall. All of them determine the different subjective feeling and quality of sound. According to the causes and requirements of these factors, the basic recommendations are put forward for theater auditorium hall design to ensure good sound effect.
11
Yoshida, Takumi, Yasutaka Ueda, Norimasa Mori, and Yumi Matano. "An Experimental Study of the Performance of a Crossed Rib Diffuser in Room Acoustic Control." Applied Sciences 11, no. 9 (April 22, 2021): 3781. http://dx.doi.org/10.3390/app11093781.
Повний текст джерелаАнотація:
This paper presents a crossed rib diffuser (CRD) as an effective tool for room acoustic control. We performed an experimental investigation of its effectiveness using a specimen manufactured for this trial. The CRD is constructed by overlapping two one-dimensional (1D) periodic rib diffusers with different specifications so that they are crossed at non-right angles. The CRD achieves a higher scattering coefficient than 1D periodic rib diffusers in a wide band while maintaining the simple and friendly design of 1D periodic rib diffusers applicable to various architectural spaces. Moreover, inserting an absorbing layer between upper and lower ribs of the CRD, (CRD-A) yields a high broadband absorption coefficient. We first evaluated the random-incidence scattering coefficient of CRD using a 1/5 scaled model in comparison with those of 1D periodic diffusers assessed with a numerical method. Then, absorption coefficients for the CRD and the CRD-A were measured using a reverberation room. Subsequently, an experiment on a small meeting room with a 1D periodic rib diffuser, the CRD and the CRD-A was conducted to present performance of the CRD in room acoustic control. Impulse response measurements and evaluations of reverberation parameters (T20 and EDT) and speech clarity (D50) were conducted. Additionally, we present differences in structure of reflected sounds found for the flat wall, the CRD and the CRD-A visually using a four-channel sound field microphone.
12
Li, Yi Hong, and Ai Ying Yang. "Acoustical Design and Measurement in Surround Sound Classroom." Applied Mechanics and Materials 105-107 (September 2011): 1839–42. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.1839.
Повний текст джерелаАнотація:
This paper covers the requirement and measurement of sound quality in the surround sound classroom. Based on the characteristics of the sound field, this paper specially deals with the design of acoustics requirement of the characteristics of reverberation frequency and sound propagation. In order to meet the requirements of recording in signal to noise ratio, comprehensive methods in noise decrease are adopted in design, which include the reduction of noise in room background. Through the checking of the testing data and the evaluation of the users, various acoustics norms meet the requirements of acoustics and the demands of the using.
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De Giorgi, Maria Grazia, Paolo Maria Congedo, Cristina Baglivo, Marina Bonomolo, and Daniele Milone. "Experimental Characterization and Acoustic Correction of a Multipurpose Performance Hall: The Italian Theatre “Cavallino Bianco”." Buildings 12, no. 9 (August 31, 2022): 1344. http://dx.doi.org/10.3390/buildings12091344.
Повний текст джерелаАнотація:
This study presents the retrofit acoustic design of the Italian theatre “Cavallino Bianco”. In its historical configuration, the hall had a curved roof with a pressed-plant fiber ceiling, which was demolished and replaced with a wooden roof without a false ceiling, leading to an increase in volume and worsening of the reverberation time. This study proposes the realization of a wave ceiling and the application of sound-absorbing and reflecting panels on the walls, which have already been implemented. These modifications have affected the acoustic characterization of the theatre, as shown both through on-site measurements during the main construction phases and through numerical simulations. The reverberation time, clarity index, and speech transmission index (STI) are evaluated considering all the variations in the hall during its different construction times, and the optimal solution is identified with regard to different specific uses. The final configuration, by reducing the volume of the hall and using sound-absorbing materials, significantly reduces the reverberation time. In addition, the hall at full capacity with chairs and people shows evident improvement to the clarity index, allowing the theatre to be used for a wide range of musical genres such as instrumental, symphonic, and opera.
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Dong, Wayland, John Lo Verde, and Samantha Rawlings. "Sound pressure-based ratings are preferred for evaluation of insitu sound isolation." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A34. http://dx.doi.org/10.1121/10.0010572.
Повний текст джерелаАнотація:
The International Building Code has recently been revised to explicitly specify the ratings to use for field ( in situ) measurements of airborne and impact sound isolation in residential properties. We review the differences between the various ratings, which (on the surface) are defined by their normalization procedure. Two normalization options are defined in current ASTM and ISO standards: a standard reverberation time of 0.5 s, and a standard amount of absorption of 10m2. It is not always appreciated that the choice of normalization is a choice of the type of measurement being performed. Normalization to a standard reverberation time is based on sound pressure and hence is a measurement of the acoustic isolation between spaces, while normalization to a standard amount of absorption is based on apparent sound power and hence is a measurement of the performance of the separating assembly. It is sometimes assumed the sound power-based ratings are representative of the sound isolation experienced by occupants, but they often provide an inaccurate assessment of the resultant isolation. Analysis and examples are presented, and it is demonstrated that the sound pressure-based ratings are preferred.
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Bean, L. W. "Direct measurement of reverberation time with a sound level meter." Applied Acoustics 26, no. 3 (1989): 231–34. http://dx.doi.org/10.1016/0003-682x(89)90056-x.
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Barron, Mike. "Developments in Concert Hall Acoustics in the 1960s: Theory and Practice." Acoustics 1, no. 3 (July 22, 2019): 538–48. http://dx.doi.org/10.3390/acoustics1030030.
Повний текст джерелаАнотація:
After the war, there was a general understanding of reverberation time (RT), including how to measure it and its significance, as well as its link to a state of diffusion. Reverberation refers to a property of late sound; there was an appreciation that early sound must be significant, but in what way? Research had begun in the 1950s using simulation systems in anechoic chambers, with the Haas effect of 1951 being the most prominent result. Thiele’s Deutlichkeit, or early energy fraction, was important from 1953 and indirectly found expression in Beranek’s initial time delay gap (ITDG) from 1962. The 1960s produced a possible explanation for RTs in halls being shorter than calculations predicted, the importance of early sound for the sense of reverberation (EDT), the nature of directional sensitivity, conditions for echo disturbance, and the importance of early lateral reflections. Much of the research in the 1960s laid the foundations for research investigating the relative importance of the various subjective effects for concert hall listening. Important concert halls built during the period include Philharmonic Hall, New York (1962); Fairfield Hall, Croydon, London (1962); the Philharmonie, Berlin (1963); and De Doelen Hall, Rotterdam (1966). The parallel-sided halls of the past were rarely copied, however, due to architectural fashion. These various halls will be discussed as they make a fascinating group.
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Nowoświat, Artur. "Impact of Temperature and Relative Humidity on Reverberation Time in a Reverberation Room." Buildings 12, no. 8 (August 21, 2022): 1282. http://dx.doi.org/10.3390/buildings12081282.
Повний текст джерелаАнотація:
Changes in acoustic parameters measured in a room may depend on the location and orientation of the sound source and microphones or on the reverberation conditions of the room. As was found in the research presented in this publication, reverberation in a room is also influenced by thermo-hygrometric conditions. The article presents an experimental analysis involving the impact of temperature and relative air humidity in a room on reverberation time. Since it is very difficult to control the temperature and relative humidity in real conditions, the tests were carried out both in laboratory conditions and with the use of simulations. For this purpose, the results of the reverberation time measurements in the reverberation chamber for various thermo-hygrometric conditions were obtained. Then, the reverberation chamber was modeled in the ODEON Version 11.0 program, and after the validation of the model, a series of simulations were performed, demonstrating the changes in the reverberation time as a function of temperature and relative air humidity. The results are presented in both a two-dimensional and three-dimensional version, i.e., the dependence of the reverberation time as a function of two variables: air temperature and relative humidity.
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Fanina, E. "EFFICIENT ACOUSTIC COMPOSITE PANELS BASED ON GRAPHITE." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 6, no. 4 (May 7, 2021): 82–90. http://dx.doi.org/10.34031/2071-7318-2021-6-4-82-90.
Повний текст джерелаАнотація:
A set of experimental studies is carried out to determine the acoustic characteristics of three-dimensional panels of fixed thickness made of carbon-based composite material installed in the opening between the reverberation chambers. Sound insulation indices are determined when they are excited by a diffuse sound field in wide frequency ranges. The reverberation time in model chambers with different partition configurations is calculated. The optimal configuration of the partition with pyramidal cells to reduce the reverberation time in the rooms is determined. The use of graphite in the form of thin membrane applied to various surfaces can significantly reduce the sound pressure levels in the room and increase the sound insulation indices of air noise. In addition to thin membrane, graphite can be used as an additive in composite materials for sound insulation purposes. It is shown that the characteristics of such panels are quite universal. The measured acoustic characteristics of composite panels are compared with similar characteristics of traditional materials. It is determined that the composition belongs to the I group of fire-retardant efficiency and can be recommended for use as a fire-retardant material. The developed acoustic material is an effective absorbing agent that solves problems in architectural acoustics, echo cancellation in construction and architecture. Similar to metamaterials, natural and artificial graphites allow to solve these problems with small volumes and masses using simple and inexpensive technologies.
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Aleshkin, Vasily, Christofor Schirjetsky, and Anton Subbotkin. "ESTIMATING SOUND ABSORPTION IN COEFFICIENT OF PRAYERS IN MOSCQUES." Akustika 32 (March 1, 2019): 227–30. http://dx.doi.org/10.36336/akustika201932227.
Повний текст джерелаАнотація:
The article deals with analysing sound absorption of prayers in big congregational mosques. Peculiarity of sound absorption measurement in prayer halls is linked with the capability of mosque worshipers to pray in different poses with diverse arrangements as opposed to the traditional halls where people usually sit in chairs. This factor has a strong influence over the sound absorption coefficient which should be taken into account in acoustical design of such buildings. Within the framework of this study sound absorption coefficients (SAC) were measured using reverberation room method for people praying on carpets in different poses. Calculated data have been
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Bliūdžius, Raimondas, Kęstutis Miškinis, Vincent Buhagiar, and Karolis Banionis. "Sound Insulation of Façade Element with Triple IGU." Buildings 12, no. 8 (August 14, 2022): 1239. http://dx.doi.org/10.3390/buildings12081239.
Повний текст джерелаАнотація:
Sound insulation design for structural glazed façade is an important task in environmental noise control, as increased continuously repeated noise is a significant factor impacting on people’s well-being and is associated with a negative impact on their health. For façades, in addition to sound insulation, requirements for safe use and high energy efficiency are also usually raised, which partly determine the composition of the glazing: triple insulating glass unit (IGU) with inner safety laminated glass sheet. Therefore, the aim of the research was to investigate the structural sealed façade structure with triple IGU and to determine the effect of the thickness of ordinary and laminated glasses, their position in the IGU, the thickness of the gas cavities, and the mass of the structural frame on the sound insulation level of structural glazing. Experimental measurements of the sound insulation index of the investigated façade elements with IGU of various constructions were performed in an acoustic reverberation chamber according to standard procedures. The result of the study indicated that the use of the second laminated glass in a triple IGU is inefficient, the highest sound insulation indicators are achieved by increasing the thicknesses of the external glass sheet and the gas cavity; increasing the mass of the frame also has only little effect on the sound insulation of the structural glazing.
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Park, Sang Bum. "Developing a virtual reality application for cultural heritage and room acoustics education." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A274. http://dx.doi.org/10.1121/10.0016250.
Повний текст джерелаАнотація:
We tend to use visual factors, such as architectural styles, features, specific decorations, historical contexts, etc., to characterize cultural heritage. Sound is a transient, ethereal phenomenon that tends to be neglected in historical records. While photographs and drawings can preserve the visual aspect of a building or scene, documenting the sonic impact of the spaces is more complicated. In particular, the historic places used for sonic activities, such as music halls, performance halls, and worship spaces, are essential to document and preserve the acoustic qualities. An immersive experience using virtual reality (VR) technology effectively promotes public awareness about cultural heritage's importance. It simulates the room acoustics using spatial audio technology. It also can make the VR environment interactive to manipulate architectural features that change the room acoustics, such as room volume, finish materials, reverberation time, sound barrier, etc. The main goal of this paper is to develop a VR application that can be used as a template to create a VR environment where 3rd to 8th-grade students navigate and learn about the history and architectural features of cultural heritage and the basics of room acoustics using a Quest headset.
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Prawda, Karolina, Sebastian J. Schlecht, and Vesa Välimäki. "Calibrating the Sabine and Eyring formulas." Journal of the Acoustical Society of America 152, no. 2 (August 2022): 1158–69. http://dx.doi.org/10.1121/10.0013575.
Повний текст джерелаАнотація:
Of the many available reverberation time prediction formulas, Sabine's and Eyring's equations are still widely used. The assumptions of homogeneity and isotropy of sound energy during the decay associated with those models are usually recognized as a reason for lack of agreement between predictions and measurements. At the same time, the inaccuracy in the estimation of the sound-absorption coefficient adds to the uncertainty of calculations. This paper shows that the error of incorrectly assumed sound absorption is more detrimental to the prediction precision than the inherent error in the formulas themselves. The proposed absorption calibration procedure reduces the differences between the measured and predicted reverberation time values, showing that an accuracy within ±10% from the target reverberation time values can be achieved regardless of the absorption distribution in a room. The paper also discusses the oft neglected air absorption of sound, which may introduce considerable bias to the measurement results. The need for an air-absorption compensation procedure is highlighted, and a method for the estimation of its parameters in octave bands is proposed and compared with other approaches. The results of this study provide justification for the use of the Sabine and Eyring formulas for reverberation time predictions.
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Nocke, Christian. "Absorption measurements—A never ending story?!" Journal of the Acoustical Society of America 151, no. 4 (April 2022): A143. http://dx.doi.org/10.1121/10.0010912.
Повний текст джерелаАнотація:
A brief historical review on measurement techniques of sound absorption or the acoustic surface impedance will be presented, starting from procedures in the 1930s. Many in situ and laboratory methods have been described over the years. Most of these methods are based on the assumption of plane wave propagation or diffuse sound field. Measurement examples will be shown for some of the methods presented and compared to each other. A commonly used measurement procedure of so-called diffuse sound absorption coefficients is described in the international standard ISO 354. The present revision of the standard only focuses on the conditioning of the sound field and further applying Sabine equation. A diffuse sound field is atheoretical approach. Geometrical acoustics as the basis of sound field simulation has been applied to measurements in a virtual reverberation chamber on absorber baffle set-ups [see Probst (2015)] and showed good agreement between measured and calculated values. This approach is used to investigate the effect of sample size and sample position. Correspondingly, non-standard measurements are compared with simulation results.
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Lai, Heather L., Anne C. Balant, and David Foote. "Case study: Measurement and treatment of severe flutter echo caused by a barrel-vaulted sanctuary ceiling." Noise Control Engineering Journal 67, no. 5 (September 1, 2019): 380–93. http://dx.doi.org/10.3397/1/376733.
Повний текст джерелаАнотація:
This case study centers on a recently constructed church with a barrel-vaulted sanctuary ceiling exhibiting excessive reverberation times and flutter echo. Reverberation times in excess of 5 s in the speech frequency range were observed at locations along the tiled center aisle, along with correspondingly elevated sound pressure levels and a highly non-diffuse sound field. Preliminary measurements, which included covering the reflective center aisle, substantiated the hypothesis that the acoustical behavior was caused by the interaction between the center aisle and the barrel-vaulted ceiling. The proposed recommendations for retrofitting the space to improve intelligibility along the aisle were modified with a view toward attaining an acceptable reduction in the reverberation times while retaining the spacious acoustical quality of the sanctuary. Additional acoustical measurements were performed prior to and following the completion of the recommended treatment. This case study describes the series of measurements and presents results of the treatment, in terms of reverberation time, impulse response decay curves, impulse response time waveforms and spectrograms, and sound pressure level measures. The unique characteristics of flutter echo due to the barrel-vaulted ceiling before and after the successful acoustical treatment are described.
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Tomiku, Reiji, Toru Otsuru, Noriko Okamoto, Takeshi Okuzono, and Youtarou Kimura. "Finite element sound field analysis for investigation on measurement mechanism of reverberation time in non-diffuse sound field." Journal of the Acoustical Society of America 140, no. 4 (October 2016): 3292. http://dx.doi.org/10.1121/1.4970467.
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Zhang, Jiahua, Juan Navarro, Ning Xiang, and Mélanie Nolan. "Finite-difference diffusion-equation modeling of reverberation chambers in time-domain." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A252. http://dx.doi.org/10.1121/10.0016179.
Повний текст джерелаАнотація:
Conventional chamber-based methods of random incidence absorbing coefficients overlook the non-diffused sound field in the room acoustics, which decreases accuracy and may even lead to conflicting results. This work applies the diffusion equation model to room-acoustic simulations of standardized reverberation chambers. The simulations can more efficiently capture the chamber's non-diffuse sound field and energy flows than wave-based simulation models. The diffusion equation represents the governing equation of reverberant sound energy densities within the reverberation chamber which is solved using the finite-difference time-domain method. Its computational efficiency of diffusion equation-based modeling lies in a highly sparse domain meshing condition dictated by the mean-free path length rather than wavelengths and still derives a wideband simulation result. This work also dedicates the effort to reexamine the meshing condition, particularly for standardized finite sizes of sound absorbers for measurements of random incidence absorption coefficients. By comparing the outcomes of simulations with measurement data, an a posteriori absorption coefficient is inversely estimated involving Bayesian parameter estimation.
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Nutter, David B., Timothy W. Leishman, Scott D. Sommerfeldt, and Jonathan D. Blotter. "Measurement of sound power and absorption in reverberation chambers using energy density." Journal of the Acoustical Society of America 121, no. 5 (May 2007): 2700–2710. http://dx.doi.org/10.1121/1.2713667.
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Kamisiński, Tadeusz, Krzysztof Brawata, Adam Pilch, Jarosław Rubacha, and Marcin Zastawnik. "Test Signal Selection for Determining the Sound Scattering Coefficient in a Reverberation Chamber." Archives of Acoustics 37, no. 4 (December 1, 2012): 405–9. http://dx.doi.org/10.2478/v10168-012-0051-2.
Повний текст джерелаАнотація:
Abstract The paper focuses on the problem of test signal selection in determining the sound scattering coefficient in accordance with ISO 17497-1. Research shows that the use of MLS signal is preferred in this procedure. The sine sweep signal, despite its advantages, presents certain limitations if the sample is moving during measurement. An attempt has been made to develop a method that allows for minimization of error, demonstrating the dependence of the obtained values of the sound scattering coefficient on the rotational speed of the turntable and type of test signal. Conditions for the application of the sine sweep signals in continuous and discrete measurements were defined.
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Rubacha, Jarosław, Adam Pilch, and Marcin Zastawnik. "Measurements of the Sound Absorption Coefficient of Auditorium Seats for Various Geometries of the Samples." Archives of Acoustics 37, no. 4 (December 1, 2012): 483–88. http://dx.doi.org/10.2478/v10168-012-0060-1.
Повний текст джерелаАнотація:
Abstract This paper presents the results of measurements of the sound absorption coefficient of auditorium seats carried out in the laboratory using two methods. In the first one, small blocks of seats in various arrangements were studied in a reverberation chamber to determine the absorption coefficient of an auditorium of infinite dimensions. The results were compared to the values of the absorption coefficient measured using the second method, which involved samples enclosed within a frame screening the side surfaces of other auditorium blocks. The results of both methods allowed for the assessment of the sound absorption coefficient of an auditorium of any dimensions while taking into account the sound absorption by the side surfaces. The method developed by the authors will simplify the currently known measurement procedures.
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Chojnacki, Bartlomiej, and Tadeusz Kamisinski. "Technical and electroacoustic aspects of miniature omnidirectional sound sources used in acoustic scale modeling." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A248. http://dx.doi.org/10.1121/10.0011218.
Повний текст джерелаАнотація:
Acoustic similarity theory allows us to create scaled room acoustic models which are simple to construct but usually difficult to measure correctly. One of the most common problems is the sound source, which works in the wide frequency range (800–40000 Hz, 500–63000 Hz) and has an omnidirectional sound propagation pattern. The lecture will present the novel approach for miniature sound sources design and creation for the most common measurement functions—laboratory objects and materials measurements (absorption, diffusion) in the scaled reverberation chamber, sound insulation scale modeling, and the room acoustic measurements in reduced models. Each of those applications has special sound source requirements, which allow us to differentiate their construction type. The most important aspects of the designing process were investigated, such as the number of transducers used and their placement, types of speakers, enclosure shape, and dimensions. The lecture will expose the sound sources used in Technical Acoustic Laboratory in AGH, Cracow, for the given measurement functions. The design recommendations developed based on FEM modeling, and experimental testing will be discussed regarding the existing objects, allowing future users to recreate in similar shape or adjust to other, predefined scale modeling measurement functions.
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Sel, Ece, İpek Düzova, Anıl Ege Şireli, Beyza Yazıcı, and Zühre Sü Gül. "Reuse of coffee waste and paper cups for acoustical panel applications in architectural studios." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 3 (August 1, 2021): 3779–89. http://dx.doi.org/10.3397/in-2021-2515.
Повний текст джерелаАнотація:
This study has been initiated with an aim of enhancing the acoustical comfort levels in the architectural studios of Bilkent University in Ankara. Initial assessment of the studios by field tests indicated very long reverberation times, supporting the complaints by the students and instructors. In order to be applied in studio environment, acoustical panels are developed out of recycled materials. The increasing coffee demand and consumption of our era have motivated the reuse of both paper cups and coffee waste. The end-product is composed of two layers. The outer layer is out of recycled coffee cups, placed in different arrangements in terms of orientation, size, and spacing. The backing layer is a panel of compressed and kiln-dried coffee grains and tea leaves. The coffee/tea residues are adhered together by using natural binders. In order to determine the best possible alternative of the waste materials with the highest sound absorption performance, different density variations have been explored. Both impedance tube tests and acoustical field measurements are utilized during the process of research and development. Considering the increasing demand for green technology, the layered panel system is proposing cost minimized, environmentally friendly, and biodegradable solutions with improved acoustical and aesthetical values.
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Barkas, Nikos. "The Contribution of the Stage Design to the Acoustics of Ancient Greek Theatres." Acoustics 1, no. 1 (March 23, 2019): 337–53. http://dx.doi.org/10.3390/acoustics1010018.
Повний текст джерелаАнотація:
The famous acoustics of ancient Greek theatres rely on a successful combination of appropriate location and architectural design. The theatres of the ancient world effectively combine two contradictory requirements: large audience capacity and excellent aural and visual comfort. Despite serious alterations resulting from either Roman modifications or accumulated damage, most of these theatres are still theatrically and acoustically functional. Acoustic research has proven that ancient theatres are applications of a successful combination of the basic parameters governing the acoustic design of open-air venues: elimination of external noise, harmonious arrangement of the audience around the performing space, geometric functions among the various parts of the theatre, reinforcement of the direct sound through positive sound reflections, and suppression of the delayed sound reflections or reverberation. Specifically, regarding the acoustic contribution of the stage building, it is important to clarify the consecutive modifications of the skene in the various types of theatres, given the fact that stage buildings were almost destroyed in most ancient Greek theatres. This paper attempts to demonstrate the positive role of the scenery in contemporary performances of ancient drama to improve the acoustic comfort using data from a sample of twenty (20) ancient theatres in Greece.
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Yau, Justin, and Brian Corry. "Loudness control in a small volume Recital Hall." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A22—A23. http://dx.doi.org/10.1121/10.0015413.
Повний текст джерелаАнотація:
Mississippi State University’s new music building features a 173-seat Lecture Hall that also serves as a recital hall. The limited volume presents an acoustical challenge to accommodate a variety of uses—most concerning are the louder and larger ensembles with up to 25 musicians and 50 singers sharing the stage. Due to project-specific constraints, the 24 foot stage-to-ceiling height and the 60,000 cubic foot volume are less than the early design-phase recommendations for the expected uses, which raises concerns about loudness buildup and inability to generate desired reverberation. Our goal is to implement variable loudness control systems that provide a useful reverberation range with good clarity across different settings. We identify and justify four loudness control strategies—maintain early, supportive reflections; shape the room to form patterns of sustained sound in areas with adjustable absorption; reduce high-frequency sustain in areas near audiences; avoid flutter echoes—and illustrate how those strategies were integrated into the architectural design through room shaping, fixed wall treatments, and deployable curtains and banners. We discuss subjective and instrumented observations about the loudness (measured in Sound Strength G), reverberation time (measured in T30), clarity (measured in Clarity Index C80), and overall character of the room response.
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Zeng, Xiangyang, Jincai Sun, and Ke'an Chen. "Technical Note: Prediction of the Characteristics of Complicated Sound Fields in Long Enclosures by a Beam-Tracing Method." Building Acoustics 9, no. 2 (June 2002): 139–50. http://dx.doi.org/10.1260/135101002760164571.
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The subject of this paper is the characterisation of the sound field in long enclosures. A beam-tracing computer model has been developed especially for the simulation of sound propagation throughout long enclosures. Surface diffusing reflection and air absorption are included in the model, which can predict the impulse response and acoustic indexes at arbitrary positions in the enclosure. This paper describes how the algorithm models the sound source, sound propagation and sound receiver. The algorithm was then tested in both common rooms and long enclosures by comparison of the measurement, theoretical calculation and prediction results. The characteristics of more complex sound fields in long enclosures, the prediction of reverberation time, early decay time and sound pressure level, etc, at individual points are discussed in terms of the algorithm. The results indicate that the primary characteristics of complicated sound fields in non-rectangular long enclosures are similar to those in rectangular ones.
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Berardi, Umberto. "A Comparison of Measurement Standard Methods for the Sound Insulation of Building Façades." Building Acoustics 19, no. 4 (December 2012): 267–82. http://dx.doi.org/10.1260/1351-010x.19.4.267.
Повний текст джерелаАнотація:
This paper focuses on the limits of measurement of the sound insulation of building façades at low frequencies. Three standard methods are compared mainly for the position of the equipment. In particular, the positions proposed by the international standard ISO 140-5 and the national standards ASTM E 966 (USA) and JIS A 1430 (Japan) are considered. The limits of measurement of the sound pressure level in front of the façade are investigated. Different placements of the external source and receiver are considered. Moreover, different placements of the receiver inside small rooms are compared by focusing on corner vs. center room positions. The uncertainties of room averaged sound pressure levels measured according to different standards are discussed. The problems of measurement of the reverberation time in small rooms and of sound insulation in irregular shaped rooms are introduced because these measurements present several critical challenges. Finally, suggestions to improve the future version of the ISO 140-5 are reported.
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Fratoni, Giulia, Dario D’Orazio, and Luca Barbaresi. "Acoustic comfort in a worship space made of cross-laminated timber." Building Acoustics 26, no. 2 (February 13, 2019): 121–38. http://dx.doi.org/10.1177/1351010x19826250.
Повний текст джерелаАнотація:
The construction of a new worship space in cross-laminated timber provides a good opportunity to include acoustic needs in the whole design development. The surface porosity and the lightweight of wooden elements may be carefully considered in order to improve the intelligibility of priests’ voice. In this work, a practical approach for obtaining a global acoustic comfort using sustainable materials is provided, using geometrical acoustic simulations. Material properties and architectural geometries were taken into account in order to evaluate subjective reverberation, speech intelligibility, and spatial perception over the whole audience. Results show how the sound energy distribution in the case study follows the sound field models proposed by scholars and how the ceiling shape—inspired by industrial sheds—contributes to the acoustic comfort of the faithfuls.
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Ondrejka, Vojtěch, Tomáš Gergeĺ, Anna Danihelová, Martin Čulík, Dagmara Bednárová, Marián Schwarz, and Miroslav Němec. "THE IMPACT OF ACOUSTIC OF SELECTED SPACES ON PERCUSSION INSTRUMENTS." Akustika, VOLUME 37 (December 15, 2020): 37–85. http://dx.doi.org/10.36336/akustika20203772.
Повний текст джерелаАнотація:
The results of the investigation of the room acoustic properties influence on the perception of the sound of percussion musical instruments are presented in the paper. At first, the acoustic properties of two rooms were determined without musical instrument. Subsequently, the acoustic properties of the rooms were determined during the presentation of cajon music. On the base of reverberation time (EDT, T30), Clarity C80, Definition D50 and bass index BI) we can conclude that the room of the Hron cinema is more suitable for musical presentation, but it cannot be considered as ideal one. The Royal Hall of Zvolen Castle has a smaller influence on the sound of a percussion instrument. The influence of room acoustic properties on the resulting sound of the instrument was evaluated only on the base of results obtained with using the objective methods by the physical quantities measurement. Finally, the design of these rooms modification is presented to achieve a better sound quality of percussion instruments.
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Zhang, Jiahua, Mélanie Nolan, Ning Xiang, and Juan Navarro. "Modeling of reverberation chambers for sound absorption measurements using a diffusion equation." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A171. http://dx.doi.org/10.1121/10.0011007.
Повний текст джерелаАнотація:
The sound field in reverberation chambers used for measuring sound absorption coefficients is usually non-diffuse, leading to inaccuracies and disagreements in the results. In this paper, a diffusion equation model is applied to simulating reverberation chambers in order to obtain reverberant energy distributions and sound energy flows of the chamber under investigation in a more efficient way than wave-based simulation models. The computational efficiency of the diffusion equation lies in the fact that the meshing condition of the simulation domain is dictated by the room's mean-free path length (MFPL). Further investigation shows one-twelfth of MFPL as the meshing condition is considered practically sufficient for obtaining random incidence absorption coefficient of standardized sample sizes. With the computational efficiency given by a meshing of up to twelfth MFPL, an inversion calculation of random incident absorption coefficients of highly absorptive materials is possible with a mixed boundary condition [Jing and Xiang, JASA 123, pp. 145–153 (2008)]. Based on analysis of both chamber-based measurements and simulated data, ways to scrutinize measurement results of absorptive materials are investigated.
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Bietz, Heinrich, Sylvia Stange-Kölling, Martin Schmelzer, and Volker Wittstock. "Loss factor measurement and indications for nonlinearities in sound insulation." Building Acoustics 26, no. 1 (December 21, 2018): 21–34. http://dx.doi.org/10.1177/1351010x18819062.
Повний текст джерелаАнотація:
The loss factor is often determined in building acoustics by measuring the structure-borne reverberation time. To do this, elements under test are excited either by a hammer or by a shaker. In several experiments with sand-lime brick walls, measured loss factors turned out to be significantly larger when hammer excitation was used instead of shaker excitation. A thorough investigation of this effect was then performed using hammer blows of different strengths and a 250-kg shaker. This way, forces are in the same order of magnitude for both excitations. Measurement results lead to the conclusion that large forces may create a nonlinear structural response. The nonlinearity is observed for a sand-lime brick wall without plastering but not for a lightweight composite wall and also not for a monolithic concrete wall. The assumption of nonlinear behaviour is furthermore supported by an additional investigation where alarm pistol shots were used to excite a sand-lime brick wall with very large airborne sound pressure levels. The airborne sound insulation of the wall turned out to be nonlinear, that is, it increased with increasing sending room levels.
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Zhang, Jiping, Zheming Wang, Heng Ma, and Weike Wang. "Field measurement of reverberation time and average absorption of one high-rise building room by road traffic noise penetrating facade." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, no. 4 (August 1, 2021): 2875–86. http://dx.doi.org/10.3397/in-2021-2248.
Повний текст джерелаАнотація:
The facade insulation (FI) is one choice for Road traffic noise (RTN) at a high-rise accommodation building nearby a motor road. The weakness of FI is from window, so the window insulation (WI) is also a prioritized descriptor. ISO16283-3 states a field method to measure FI using RTN. However, in room acoustics, besides FI, reverberation time (RBT) or indoor average sound absorption (IASB) are another two un-ignorable descriptors. When the value of IASB is small, the indoor noise is not only contributed from penetrating façade RTN, but also supplemented by the residual sound from high reverberation field, weakening FI. As a parallel to ISO16283-3, this paper suggests an engineering method to measure RBT and IASB of one high-rise building room close to a motor road by penetrating façade RTN. It can supply a convenient tool for the field measurement of RBT and IASB with RTN. At the end, we made a field measurement of RBT, IASB, and WI at a hotel room nearby a viaduct in Hangzhou of China, assistant to adjust RBT or IASB and WI so as to improve the sound quality of the hotel. Further, the method can extend to the lines of rail, aviation, and shipping.
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Panza, Michael J. "An Image Based Mathematical Model for the Propagation of Fan Noise in a Plenum with Large Side Openings." Advances in Acoustics and Vibration 2015 (October 4, 2015): 1–8. http://dx.doi.org/10.1155/2015/361678.
Повний текст джерелаАнотація:
This paper presents another application of an images group model for a special enclosure geometry and source orientation. A previous work outlined the concept via application to a special tight-fitting enclosure. Application of the concept to a fan plenum requires different mathematical descriptions for the image groups. This paper describes the sound reverberation inside a sound enclosure with mostly open sides where the primary noise sources are the air inlets and exhausts of axial type fans located at the top of the enclosure, the sound transmission through the air inlet openings, and the radiation to wayside positions. The main reverberation between the floor and ceiling is determined with an image based mathematical model. The model considers how the main reverberant part image group is amplified by its images from two parallel bulkheads and any side wall frame members. The method of images approach allows the hard surfaces of an untreated plenum to be represented by perfectly reflecting surfaces with zero sound absorption coefficients, thus not requiring any estimate or measurement for these surfaces. Numerical results show excellent comparison to experimental results for an actual plenum. The image model is also shown to be significantly more accurate than the standard large room diffuse field reverberant model.
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Akil, H. A., and D. J. Oldham. "Determination of The Scattering Parameters of Fittings in Industrial Buildings for Use in Computer Based Factory Noise Prediction Models: Part 2 – Scale Model Experiments." Building Acoustics 2, no. 3 (September 1995): 527–48. http://dx.doi.org/10.1177/1351010x9500200304.
Повний текст джерелаАнотація:
In a companion paper results obtained from computer simulation1 have demonstrated that the sound propagation characteristics of disproportionate rooms are determined by the product of the fitting parameters scattering cross-section (Q) and absorption coefficient (αobst) of fittings. It was also proposed that the absorption of a fitting as measured in a conventional reverberation chamber is equivalent to four times the product of those two parameters. This suggests that measurement of fitting absorption in a conventional reverberation chamber could provide the data required for input into current computer based factory noise prediction models. Since both parameters are required as inputs to computer models it would be necessary to separate them in some way from the data obtained in the reverberation chamber. In this paper two methods for determining the scattering parameters of fittings in industrial buildings based upon acoustical measurements are described. The accuracy of these is compared with that resulting from the application of a geometrical measurement method to determine the scattering cross-section (Q) of various shapes of model scatterers employed in experimental work employing 1:20 acoustic scale models. The values of Q obtained from each method were used to predict sound characteristics a model disproportionate chamber using RAYSCAT. The predicted results obtained from the computer model by inputting the values of Q determined using the acoustical measurement methods were found to be more accurate than those using the geometrical measurement method.
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Zechmann, Edward. "Advancing support for cause-and-effect models by estimating the kurtosis statistic using fractional-octave-band filters." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 264, no. 1 (June 24, 2022): 247–58. http://dx.doi.org/10.3397/nc-2022-725.
Повний текст джерелаАнотація:
This paper presents a preliminary method for estimating signal processing parameters that optimally satisfies accuracy and resolution requirements for the sound pressure level and kurtosis level. The kurtosis statistic has long been studied and more recently used for applications in acoustics and vibrations such as architectural acoustics, hearing loss, noise exposure, and accelerated material and structural life testing. The temporal and spectral characteristics of many quantities are evident by time-frequency analysis including hearing, finger sensation, sound diffusion, and reverberation. Some research has conditioned on frequency content while other research has not. Simpson's reversal may potentially adversely affect the models if frequency content is not considered. Modeling techniques which relate cause-and-effect are more likely to result in successful models. Models of human hearing are particularly sensitive to the frequency content because the tonotopic organization of the cochlea induces a cause-and-effect relationship from sound incident on the ear to the basilar membrane. The fractional-octave-band filters specified in ANSI S1.11 and IEC 61260-1 are well developed for conditioning on frequency bands. This paper provides details of the process for optimizing the filter parameters. Additional optimization and testing is described for developing a faster and more accurate method with better support for causal inference.
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Labia, Laura, Louena Shtrepi, and Arianna Astolfi. "Improved Room Acoustics Quality in Meeting Rooms: Investigation on the Optimal Configurations of Sound-Absorptive and Sound-Diffusive Panels." Acoustics 2, no. 3 (June 27, 2020): 451–73. http://dx.doi.org/10.3390/acoustics2030025.
Повний текст джерелаАнотація:
This work deals with the improvement of the room acoustic quality of two medium sized meeting rooms through the investigation of the optimal placement of absorption and diffusive panels on the walls and ceiling. Acoustic measurements have been carried out in the existing untreated rooms with ODEON 13 room acoustics measurement and prediction software, and the Adobe Audition plugins Aurora. Simulations of different combinations of sound absorption and diffusion treatments have been carried out with the updated version of the software, ODEON 15. The panels were positioned in the meeting rooms following the guidelines of the DIN 18041 standard and the scientific literature. The results advise the application of absorptive materials on the ceiling or around the borders, creating a reflective middle area, and on the upper part of one the lateral walls, including the rear wall. Configurations with diffusers do not generally bring significant improvements. The Speech Transmission Index (STI) is a less sensitive parameter for the different acoustic scenarios, compared to Reverberation Time (T) and Clarity (C50). The research also outlined a design workflow, useful to successfully design meeting rooms and rooms for speech in general, which allows to determine the optimal number and location of acoustic panels and to minimize the costs.
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TSAY, Yaw-Shyan, and Chiu-Yu YEH. "A Machine Learning Based Prediction Model for the Sound Absorption Coefficient of Micro-Expanded Metal Mesh (MEMM)." Applied Sciences 10, no. 21 (October 28, 2020): 7612. http://dx.doi.org/10.3390/app10217612.
Повний текст джерелаАнотація:
Recently, micro-perforated panels (MPP) have become a popular sound absorbing material in the field of architectural acoustics. However, the cost of MPP is still high for the commercial market in Taiwan, and MPP is still not very popular compared to other sound absorbing materials and devices. The objective of this study is to develop a prediction model for MEMM via a machine learning approach. An experiment including 14 types of MEMM was first carried out in a reverberation room based on ISO 354. To predict the sound absorption coefficient of the MEMM, the capability of three conventional models and three machine learning (ML) models of the supervised learning method were studied for the development of the prediction model. The results showed that in most conventional models, the sound absorption coefficient of using an equivalent perimeter had the best agreement compared with other parameters, and the root mean square error (RMSE) between prediction models and experimental data were around 0.2~0.3. However, the RMSE of all ML models was less than 0.1, and the RMSE of the gradient boost model was 0.033 in the training sets and 0.062 in the testing sets, which showed the best agreement with the experiment data.
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Bondan Dwisetyo, Maharani Ratna Palupi, and Fajar Budi Utomo. "UNCERTAINTY ANALYSIS OF LABORATORY MEASUREMENT OF AIRBORNE SOUND INSULATION." Spektra: Jurnal Fisika dan Aplikasinya 5, no. 2 (August 31, 2020): 97–108. http://dx.doi.org/10.21009/spektra.052.02.
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The evaluation and analysis of the uncertainty of laboratory measurement of airborne sound insulation have been carried out by Research Group for Acoustics and Vibration – National Standardization Agency of Indonesia (BSN). The aims of this work are to evaluate and analyze the uncertainty measurement of airborne sound insulation by pressure method, where it is focused only for the determination of sound transmission loss (STL) as a major product of this measurement according to ASTM, and guide to the expressions of Uncertainty in Measurement (GUM) provided by JCGM. The supplied parameter of uncertainty budgets includes measurement of sound pressure level (SPL) in a source room (L1), and measurement of some parameters in a receiver room such as SPL (L2), reverberation time (RT60), background noise (B), test opening area (S), and volume of receiver room (V). From the result of the case study, the source of uncertainty that has a top contribution for obtaining expanded uncertainty is considered as the repeated measurement of the measured parameter such as L1, L2, and RT60 at the frequency range 250 Hz – 315 Hz. Meanwhile, the standard uncertainty that provided by the calibration certificate also contributes to the final result, where it is supplied by an acoustic calibrator and sound analyzer, respectively. Furthermore, the sources obtained from the readability parameter has a slight effect on this whole result. Therefore, the maximum and minimum value of expanded uncertainty is determined that their values are 0.70 dB and 0.43 dB for the frequency of 315 Hz and 1600 Hz, respectively.
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Zapata-Rodriguez, Valentina, Søren Laugesen, Cheol-Ho Jeong, Jonas Brunskog, and James Harte. "Do Room Acoustics Affect the Amplitude of Sound-Field Auditory Steady-State Responses?" Trends in Hearing 25 (January 2021): 233121652096502. http://dx.doi.org/10.1177/2331216520965029.
Повний текст джерелаАнотація:
The sound-field auditory steady-state response (ASSR) is a promising measure for the objective validation of hearing-aid fitting in patients who are unable to respond to behavioral testing reliably. To record the sound-field ASSR, the stimulus is reproduced through a loudspeaker placed in front of the patient. However, the reverberation and background noise of the measurement room could reduce the stimulus modulation used for eliciting the ASSR. As the ASSR level is heavily dependent on the stimulus modulation, any reduction due to room acoustics could affect the clinical viability of sound-field ASSR testing. This study investigated the effect of room acoustics on the level and detection rate of sound-field ASSR. The study also analyzed whether early decay time and an auditory-inspired relative modulation power model could be used to predict the changes in the recorded ASSR in rooms. A monaural auralization approach was used to measure sound-field ASSR via insert earphones. ASSR was measured for 15 normal-hearing adult subjects using narrow-band CE-Chirps® centered at the octave bands of 500, 1000, 2000, and 4000 Hz. These stimuli were convolved with simulated impulse responses of three rooms inspired by audiological testing rooms. The results showed a significant reduction of the ASSR level for the room conditions compared with the reference anechoic condition. Despite this reduction, the detection rates for the first harmonics of the ASSR were unaffected when sufficiently long recordings (up to 6 min) were made. Furthermore, the early decay time and relative modulation power appear to be useful predictors of the ASSR level in the measurement rooms.
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Targowski, Wojciech, and Andrzej Kulowski. "Influence of the Widespread Use of Corten Plate on the Acoustics of the European Solidarity Centre Building in Gdańsk." Buildings 11, no. 3 (March 23, 2021): 133. http://dx.doi.org/10.3390/buildings11030133.
Повний текст джерелаАнотація:
This paper describes the relationship between a strong architectural vision that is difficult to balance, and user expectations in terms of acoustics. The focus is on the use of corten steel as the dominant finishing material on façades and interiors to achieve an expressive, symbolic message through program-based design. The architectural premises justifying the adopted solutions are presented, especially the universality and homogeneity of the material. Against this background, the influence of corten steel on the acoustics of the two largest rooms of the European Solidarity Center, which are the winter garden and the multi-purpose hall, was discussed. Remedial steps have been taken to reduce the greatest acoustic inconveniences resulting from the widespread use of metal sheet as a finishing material in rooms, i.e., excessive reverberation and a low degree of sound dispersion. A positive result for the acoustic conditions achieved in the winter garden was the presentation of a large body of classical music in the building.
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Zhou, Xiao Hui. "Study of the Application of Architectural Acoustic Materials in Sports Venues." Advanced Materials Research 507 (April 2012): 83–87. http://dx.doi.org/10.4028/www.scientific.net/amr.507.83.
Повний текст джерелаАнотація:
This paper briefly introduces the use of sound-absorbing materials and sound-proof materials in the buildings, concisely summarizes the factors taken into account in the acoustic design, and then introduces the requirements of architectural acoustics materials in sports venues. It ultimately introduces the general requirements for acoustic measurement. Therefore, we can draw some conclusions. On the one hand, it is necessary to strengthen basic research, technical measures and organizational management practices in acoustic materials. On the other hand, we should pay more attention to transmission channels and reception conditions. At last, it is necessary to establish cooperation with various professions for comprehensive study, with a view to obtaining the best technical performance and economic benefits.
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Pham Vu, Thach, and Hervé Lissek. "Low frequency sound field reconstruction in a non-rectangular room using a small number of microphones." Acta Acustica 4, no. 2 (2020): 5. http://dx.doi.org/10.1051/aacus/2020006.
Повний текст джерелаАнотація:
An accurate knowledge of the sound field distribution inside a room is required to identify and optimally locate corrective measures for room acoustics. However, the spatial recovery of the sound field would result in an impractically high number of microphones in the room. Fortunately, at low frequencies, the possibility to rely on a sparse description of sound fields can help reduce the total number of measurement points without affecting the accuracy of the reconstruction. In this paper, the use of Greedy algorithm and Global curve-fitting techniques are proposed, in order to first recover the modal parameters of the room, and then to reconstruct the entire enclosed sound field at low frequencies, using a reasonably low set of measurements. First, numerical investigations are conducted on a non-rectangular room configuration, with different acoustic properties, in order to analyze various aspects of the reconstruction frameworks such as accuracy and robustness. The model is then validated with an experimental study in an actual reverberation chamber. The study yields promising results in which the enclosed sound field can be faithfully reconstructed using a practically feasible number of microphones, even in complex-shaped and damped rooms.