Trial applications at gymnasiums of in-situ sound absorption measurement method by ensemble averaging technique

The authors have been published a series of papers on a measurement method for sound absorption characteristics of materials using ensemble averaging technique, i.e., EA method. The papers' results included measurement mechanisms, measurement uncertainty, and so on. Herein, to examine adaptability, especially in in-situ conditions, the EA method is applied to measure absorption characteristics of materials installed in two gymnasiums. A glass-wool panel with the dimension of 0.5 m by 0.5 m by 0.05 m and with the density of 32 kg m^-3 was brought around and measured to check the measurement consistency. Several measurements were conducted during badminton plays were undergoing. Measured sound absorption coefficients revealed that most results agree well with those measured in reverberation rooms. Certain improvement is necessary for the specimen brought to the in-situ measurement to keep the consistency. The inconsistency is considered to originate from unstable conditions between the specimen and floor.

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APPLICATION OF AN IN-SITU MEASUREMENT METHOD USING ENSEMBLE AVERAGING TECHNIQUE TO MATERIAL DEVELOPMENT

AIJ Journal of Technology and Design ◽

10.3130/aijt.21.167 ◽

2015 ◽

Vol 21 (47) ◽

pp. 167-170 ◽

Cited By ~ 1

Author(s):

Reiji TOMIKU ◽

Noriko OKAMOTO ◽

Toru OTSURU ◽

Takaaki KAMIMIZU ◽

Makoto YAMAGUCHI

Keyword(s):

Measurement Method ◽

In Situ Measurement ◽

Ensemble Averaging ◽

Averaging Technique ◽

Material Development

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Comparison of sound absorption characteristics measured by impedance tube method and ensemble averaging technique on porous clay bricks

Acoustical Science and Technology ◽

10.1250/ast.42.154 ◽

2021 ◽

Vol 42 (3) ◽

pp. 154-157

Author(s):

Siwat Lawanwadeekul ◽

Reiji Tomiku ◽

Noriko Okamoto ◽

Toru Otsuru ◽

Masahiro Masuda ◽

...

Keyword(s):

Sound Absorption ◽

Ensemble Averaging ◽

Impedance Tube ◽

Averaging Technique ◽

Clay Bricks ◽

Impedance Tube Method ◽

Absorption Characteristics

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Calculation of statistical absorption coefficient using ensemble averaged surface normal impedance of material

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-3163 ◽

2021 ◽

Vol 263 (1) ◽

pp. 5578-5583

Author(s):

Noriko Okamoto ◽

Toru Otsru ◽

Reiji Tomiku ◽

Masahiro Masuda ◽

Arisa Tabaru

Keyword(s):

Absorption Coefficient ◽

Sound Absorption ◽

Building Materials ◽

Sound Field ◽

Ensemble Averaging ◽

Absorption Coefficients ◽

Surface Normal ◽

And Control ◽

Absorption Characteristics

To predict and control the indoor sound field, it is important to comprehend sound absorption characteristics of building materials. In the previous studies, the authors have proposed an in-situ sound absorption measurement method of materials using ensemble averaging technique, namely EA method. The method yields a simple and efficient in-situ measurement of surface normal impedance of materials at random-incidence. In this paper, the authors calculate the statistical absorption coefficient using the surface normal impedance of material by the EA method to obtain random incidence absorption coefficient. At first, the procedure of calculating the statistical absorption coefficient from the normal impedance by EA method is described. Next, the sound absorption characteristics for five kinds of materials are measured by the EA method and the reverberation room method. Finally, the statistical absorption coefficients are calculated from results obtained by the EA method and are compared with absorption coefficients by the reverberation room method.

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Reproducibility of sound absorption and surface impedance of materials measured in a reverberation room using ensemble averaging technique with a pressure-velocity sensor and improved calibration

Applied Acoustics ◽

10.1016/j.apacoust.2018.08.009 ◽

2018 ◽

Vol 142 ◽

pp. 87-94 ◽

Cited By ~ 4

Author(s):

Noriaki Sakamoto ◽

Toru Otsuru ◽

Reiji Tomiku ◽

Saki Yamauchi

Keyword(s):

Surface Impedance ◽

Sound Absorption ◽

Ensemble Averaging ◽

Velocity Sensor ◽

Averaging Technique

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Exploration of the differences between a pressure-velocity based in situ absorption measurement method and the standardized reverberant room method

The Journal of the Acoustical Society of America ◽

10.1121/1.4806593 ◽

2013 ◽

Vol 133 (5) ◽

pp. 3582-3582

Author(s):

Peter Cats ◽

Emiel Tijs ◽

Daniel Fernandez Comesana

Keyword(s):

Measurement Method ◽

Absorption Measurement ◽

In Situ Absorption

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Sound absorption deviation measured using pressure–velocity sensors by ensemble averaging technique under different relative humidity conditions

Applied Acoustics ◽

10.1016/j.apacoust.2017.02.015 ◽

2017 ◽

Vol 122 ◽

pp. 121-127 ◽

Cited By ~ 3

Author(s):

Toru Otsuru ◽

Reiji Tomiku ◽

Noriko Okamoto ◽

Saki Yamauchi

Keyword(s):

Relative Humidity ◽

Sound Absorption ◽

Ensemble Averaging ◽

Averaging Technique

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Sound absorption measurement of road surface with in situ technology

Applied Acoustics ◽

10.1016/j.apacoust.2014.07.009 ◽

2015 ◽

Vol 88 ◽

pp. 12-21 ◽

Cited By ~ 10

Author(s):

Mingliang Li ◽

Wim van Keulen ◽

Emiel Tijs ◽

Martin van de Ven ◽

André Molenaar

Keyword(s):

Sound Absorption ◽

Absorption Measurement ◽

Road Surface

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Laboratory and in situ sound absorption measurement under a synthetized diffuse acoustic field

Building Acoustics ◽

10.1177/1351010x19870307 ◽

2019 ◽

Vol 26 (4) ◽

pp. 223-242

Author(s):

Olivier Robin ◽

Alain Berry ◽

Celse Kafui Amédin ◽

Noureddine Atalla ◽

Olivier Doutres ◽

...

Keyword(s):

Acoustic Field ◽

Sound Absorption ◽

Low Frequency ◽

Sound Field ◽

Geometrical Parameters ◽

In Situ Conditions ◽

Field Excitation ◽

Acoustic Environments ◽

Field Sound

This article reports numerical and experimental results concerning the estimation of the diffuse field sound absorption coefficient of several different materials under a synthetized diffuse acoustic field excitation in laboratory and in situ conditions. The proposed measurement method is based on a sound field reproduction approach and a synthetic array of acoustic monopoles facing the material to be tested. Numerical simulations are first conducted to optimize the geometrical parameters of the method and to compute theoretical sound absorption coefficients of the considered materials. Measurements on a set of six typical acoustic materials are then conducted following the standardized reverberant room method as well as the proposed approach in a hemi-anechoic room and in two realistic rooms. Albeit showing limitations in the low-frequency domain, the proposed method enables a significant reduction of the tested specimen dimensions compared with the reverberant room method and allows performing tests in non-ideal acoustic environments.

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