Improving traffic noise transmission loss of plenum windows by using sound scatterer arrays

2018 ◽  
Vol 143 (3) ◽  
pp. 1715-1715 ◽  
Author(s):  
Shiu-Keung Tang
Keyword(s):  
Transmission Loss ◽  
Traffic Noise ◽  
Noise Transmission

Empirical prediction of traffic noise transmission loss across plenum windows

2019 ◽  
Vol 151 ◽  
pp. 45-54 ◽  
Author(s):  
Xiaolong Li ◽  
Y.G. Tong ◽  
S.K. Tang ◽  
K.K. Lau
Keyword(s):  
Transmission Loss ◽  
Traffic Noise ◽  
Empirical Prediction ◽  
Noise Transmission

Technical Notes: Practical Concerns Associated with Single-Number Ratings in Measuring Sound Transmission Loss Properties of Partition Panels

2013 ◽  
Vol 38 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Naveen Garg ◽  
Anil Kumar ◽  
Sagar Maji
Keyword(s):  
Swot Analysis ◽  
Transmission Loss ◽  
Traffic Noise ◽  
Aircraft Noise ◽  
Sound Insulation ◽  
Noise Sources ◽  
Significant Dependence ◽  
Single Number ◽  
Spectrum Adaptation ◽  
Lower Frequencies

Abstract The paper presents an extensive review investigating the practical aspects related to the use of single- number ratings used in describing the sound insulation performance of partition wall panels and practical complications encountered in precise measurements in extensive frequency range from 50 Hz to 5 kHz. SWOT analysis of various single number ratings is described. A laboratory investigation on a double wall partition panel combination revealed the significant dependence of STC rating on transmission loss at 125 Hz attributed to 8 dB rule. An investigation conducted on devising alternative spectrums of aircraft noise, traffic noise, vehicular horn noise and elevated metro train noise as an extension to ISO 717-1 Ctr for ascertaining the sound insulation properties of materials exclusively towards these noise sources revealed that the single-number rating Rw + Ctr calculated using ISO 717-1 Ctr gives the minimum sound insulation, when compared with Rw + Cx calculated using the alternative spectrums of aircraft noise, traffic noise, etc., which means that material provides a higher sound insulation to the other noise sources. It is also observed that spectrum adaptation term Cx calculated using the spectrum of noise sources having high sound pressure levels in lower frequencies decreases as compared to ISO 717-1 Ctr owing to significant dependence of Ctr at lower frequencies.

Optimization of Noise Transmission Through Sandwich Structures

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Mohamed Guerich ◽  
Samir Assaf
Keyword(s):  
Sandwich Plate ◽  
Transmission Loss ◽  
Sandwich Structures ◽  
Acoustic Medium ◽  
Element Formulation ◽  
Sound Power ◽  
Surface Mass ◽  
Various Boundary Conditions ◽  
Design Variables ◽  
Noise Transmission

An optimization methodology to increase the noise transmission loss (TL) of damped sandwich structures is presented. The prediction of the TL uses a numerical tool based on a finite element formulation for the sandwich plate coupled to a boundary element method for the acoustic medium. This tool can be used for arbitrarily shaped three-layer sandwich plates with various boundary conditions and it is well adapted to parametric and optimization studies. First, a parametric study was conducted to choose the objective function, the constraints, and the pertinent design variables to use in the optimization problem which consist in reducing the sound power transmitted by a viscoelastically damped sandwich plate. Next, by constraining the acoustical behavior of the sandwich panel, the surface mass of the sandwich structure was minimized. It is shown that a significant reduction in the transmitted sound power can be achieved by selecting the appropriate geometric configuration and damping layer material.

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