Assessment of the sound reduction index of building elements by near field excitation through an array of loudspeakers and structural response measurements by laser Doppler vibrometry

This paper describes the procedure followed to evaluate the vibration reduction index for T-junctions with inserted flexible elements and proposes new equations to complement the standard EN 12354-1:2000. The experiment described in this work is based on a 1:3 scale model of a T-junction with a flexible interlayer. It was used to obtain a significant reduction in the cost of the configurations under study. We chose to carry out vibration measurements by near-field acoustic holography (NAH) in order to avoid the risk of accelerometer interference. Flanking transmission was determined for different elastic layers with the objective of quantifying the effect of the flexible interlayer and to compare the results obtained with predictive formulas. The results enabled us to propose new equations to complement EN 12354-1:2000 for the reliable prediction of the apparent sound reduction index. The uncertainty associated with the different average velocity levels is determined according to the Guide for the Expression of Uncertainty of Measurement (GUM).

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Laser Doppler vibrometry and near-field acoustic holography: different approaches for surface velocity distribution measurement

10.1117/12.468187 ◽

2002 ◽

Cited By ~ 2

Author(s):

Milena Martarelli ◽

Gian M. Revel ◽

Enrico P. Tomasini

Keyword(s):

Velocity Distribution ◽

Near Field ◽

Laser Doppler ◽

Surface Velocity ◽

Acoustic Holography ◽

Laser Doppler Vibrometry ◽

Distribution Measurement

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Laser Doppler vibrometry and near-field acoustic holography: Different approaches for surface velocity distribution measurements

Mechanical Systems and Signal Processing ◽

10.1016/j.ymssp.2005.11.011 ◽

2006 ◽

Vol 20 (6) ◽

pp. 1312-1321 ◽

Cited By ~ 22

Author(s):

M. Martarelli ◽

G.M. Revel

Keyword(s):

Velocity Distribution ◽

Near Field ◽

Laser Doppler ◽

Surface Velocity ◽

Acoustic Holography ◽

Laser Doppler Vibrometry

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Revisions to the EN12354 prediction method of calculating the flanking sound reduction index of lightweight building elements

The Journal of the Acoustical Society of America ◽

10.1121/1.4708417 ◽

2012 ◽

Vol 131 (4) ◽

pp. 3319-3319

Author(s):

Jeffrey Mahn ◽

John Pearse

Keyword(s):

Prediction Method ◽

Sound Reduction ◽

Reduction Index ◽

Building Elements

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AN EXPERIMENTAL INVESTIGATION OF ACOUSTIC PARAMETERS OF THE LABORATORY FOR MEASURING SOUND INSULATION OF BUILDING ELEMENTS/STATINIO ELEMENTŲ GARSO IZOLIACIJAI MATUOTI SPECIALIAI ĮRENGTOS LABORATORIJOS AKUSTINIŲ PARAMETRŲ TYRIMAS IR DERINIMAS

Journal of Civil Engineering and Management ◽

10.3846/13921525.2001.10531718 ◽

2001 ◽

Vol 7 (2) ◽

pp. 166-173

Author(s):

Vidmantas Dikavičius ◽

Raimondas Bliūdžius

Keyword(s):

Experimental Investigation ◽

Optimum Combination ◽

Sound Insulation ◽

Good Precision ◽

Reverberation Time ◽

Acoustic Parameters ◽

Frequency Bands ◽

Sound Reduction ◽

Reduction Index ◽

Building Elements

The report deals with a task of investigating and adjusting acoustic parameters of the reverberant chambers of recently built laboratory for measuring sound insulation properties of building elements (windows, doors). The reverberation time values in the source and receiving empty rooms were measured at 16 one-third-octave frequency bands. It was determined that they significantly exceed the recommended ones. After a number of measurements the reverberation time was adjusted to the allowable limits. An optimum combination of loudspeaker positions in the source room with respect to the best acoustic field diffusivity has been experimentally found. Repeatability values r were calculated from the measurements of sound reduction index of plastic window conducted under repeatability conditions. At the 16 one-third-octave frequency bands they show a good precision of the test equipment.

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