Insertion loss by concrete noise barrier - Acoustical testing and computational simulation

This study is concerned with the theoretical solution to the problem of sound screening by simple hard barriers on the ground with special emphasis given to the type of wave incidence, namely a comparison between the use of either a spherical or a cylindrical sound source. For a receiver at the shadow of the noise source, the field may be assumed to be due to the edge wave and for this, exact solutions are used. Regarding the wave reflection on an impedance ground, exact formulations are also used, and finally, some calculations are made on the performance of a hard noise barrier on a two-impedance ground. As a conclusion, it is found that although the sound level at the receiver may show some small differences depending on the frequency and on the geometry of the problem, the overall insertion loss of the thin hard barrier is almost the same for the spherical and the line source, and the differences are found to amount to less than 1 dB for geometries of practical occurrence.

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STUDY ON EFFECTIVE NOISE BARRIER AT SENIOR HIGH SCHOOL (SMAN 02) CIBINONG

INDONESIAN JOURNAL OF URBAN AND ENVIRONMENTAL TECHNOLOGY ◽

10.25105/urbanenvirotech.v0i0.4360 ◽

2019 ◽

Vol 2 (2) ◽

pp. 181

Author(s):

Aulia Ramandha ◽

Wisnu Eka Yulyanto ◽

Sandra Madonna

Keyword(s):

High School ◽

Insertion Loss ◽

Noise Level ◽

Road Traffic ◽

Traffic Noise ◽

Road Traffic Noise ◽

Type Ii ◽

Noise Barrier ◽

Barrier Type ◽

The Difference

Aim: The aim of this study is to design noise barrier shapes and to investigate its effectiveness in reducing traffic noise at one public school in Indonesia. Methodology and Results: Two types of barriers were designed on a laboratory scale using plywood materials and the noise level was measured using Noise Analyzer Briiel and Kjaer Type 2250. Noise reduction was analyzed by using the Insertion Loss method based on the difference of the noise level before and after implementing the barrier. The results show that the barrier Type II with a length of 200 cm, a receiver height of 30 cm, and a curved shape of 45° angle (Type L) is more effective in reducing the noise than the other variation of barrier shape and length. Barrier Type L (Type II) can reduce the noise at high frequency between 1–8 kHz with an Insertion Loss value of 6.9–27.9 dB. Conclusion, significance and impact study: The noise barrier Type II, with specifications of 20 m length, 3 m height, and barrier material of reinforced concrete, is recommended to be used at the high school to reduce the road traffic noise.

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Analysis on Traffic Noise Attenuation by Using Sound Barrier

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.584-586.776 ◽

2014 ◽

Vol 584-586 ◽

pp. 776-779

Author(s):

Xian Feng Huang ◽

Chen Hui Zhu ◽

Quan Shi

Keyword(s):

Sound Source ◽

Insertion Loss ◽

Traffic Noise ◽

Noise Attenuation ◽

Noise Barriers ◽

Sound Barrier ◽

Noise Barrier ◽

Significant Attenuation ◽

Infinite Line ◽

Insertion Losses

By applying noise insertion loss predicting model of the noise barriers, influencing factors on insertion loss of the sound barrier are investigated for achieving the significant attenuation effects. In term of the infinite line sound source and the finite length of the barriers, the sound insertion losses with varying parameters are calculated and compared. Finally, the meaningful results indicate that the economic and reasonable height and length of the noise barrier are gained to be beneficial for barrier design.

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Insertion loss calculation and parameter sensitivity analysis for noise barrier with T-shape top structure

Advances in Engineering Materials and Applied Mechanics ◽

10.1201/b19268-26 ◽

2015 ◽

pp. 143-150

Keyword(s):

Sensitivity Analysis ◽

Insertion Loss ◽

Parameter Sensitivity ◽

Parameter Sensitivity Analysis ◽

Loss Calculation ◽

Noise Barrier

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Possibilities of Evaluating the Effectiveness of Noise Barriers in Slovakia

Applied Sciences ◽

10.3390/app112110206 ◽

2021 ◽

Vol 11 (21) ◽

pp. 10206

Author(s):

Alžbeta Pultznerová ◽

Ján Šimo ◽

Juraj Grenčík

Keyword(s):

Insertion Loss ◽

Urban Areas ◽

Indirect Method ◽

Material Design ◽

Sound Insulation ◽

Noise Barriers ◽

Advantages And Disadvantages ◽

Airborne Sound ◽

A Value ◽

Noise Barrier

This paper presents environmental acute problems from increasing noise levels caused by automobile and rail transport. Noise barriers are considered to be an effective element in reducing noise in densely populated urban areas. However, do these barriers have the correct height, shape, material design, and construction? In the materials and methods, the basic characteristics of noise barrier, sound absorption, and sound insulation are described. Further, measurement methods of the insertion loss of outdoor noise barriers of all types using the direct and indirect method according to standard ISO 10847 and the Adrienne method according to standards EN 1793-5 and EN 1793-6 are presented. The measurement results of insertion loss of the selected noise barrier obtained by the indirect method showed a value of 19.1 dB(A) of insertion loss. This result was compared with simulation by our own software based on the CNOSSOS methodology, giving value of 19.6 dB(A), which is a good correlation. The Adrienne method was used for determination of the airborne sound insulation index of another noise barrier, giving a value of the single-number rating of the sound insulation of the barrier of 28 dB. In discussion, according to EN 1793-2, this value assigns an insulation index of category D3, which means that the barrier is high quality and has satisfactory airborne sound insulation. The advantages and disadvantages of both methods according to STN ISO 10847 and STN EN 1793-6 were discussed. We concluded that the main advantage of the method Adrienne—TN EN 1793-6 is that it can be used in situ under direct sound field conditions and can directly evaluate the sound insulation index of the whole barrier structure.

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Florida Noise Barrier Evaluation and Computer Model Validation

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1859-09 ◽

2003 ◽

Vol 1859 (1) ◽

pp. 72-78 ◽

Cited By ~ 2

Author(s):

Roger Wayson ◽

John MacDonald ◽

Ahmed EI-Assar ◽

Win Lindeman ◽

Mariano Berrios

Keyword(s):

Insertion Loss ◽

Traffic Noise ◽

Sound Level ◽

Noise Model ◽

Barrier Method ◽

Noise Barriers ◽

Zone Length ◽

Sound Levels ◽

Noise Barrier ◽

Source Level

The results of a project that investigated the effectiveness of in situ noise barriers in Florida are presented. The prediction accuracy of the FHWA Traffic Noise Model (TNM) is compared with STAMINA 2.0 and 2.1 (Florida-specific). A total of 20 barrier sites were visited during a 3-year period that resulted in 844 discrete 20-min equivalent sound level (Leq) measurements behind the barriers. Barrier insertion loss was determined using the ANSI indirect barrier method. A methodology was developed to estimate shadow zone length created behind highway noise barriers. All of the barriers tested were effective (>5 dB:LAeq insertion loss at distances equivalent to the first row of homes, where LAeq is the A-weighted Leq) except one site because of marginal additional shielding from a berm–barrier combination. Only three sites had an insertion loss of less than 5 dB at distances representative of the second row of homes. Overall, measurements indicate that the barriers provide substantial sound level reduction for residents along the highway. TNM was the best prediction model when considering all test sites; however, the STAMINA models were more accurate at predicting source level. TNM predictions using the Average pavement input overpredicted the reference sound levels measured at these sites. TNM predictions using the OGAC (open-graded asphalt concrete) input were improved (under 2 dB:LAeq of error) over those using the Average pavement type input. This result is expected because Florida uses an open-graded asphalt friction mix.

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