Sound Absorption for Noise Control and Room-Acoustical Design

2013 ◽  
pp. 15-30
Author(s):  
Helmut V. Fuchs
Keyword(s):  
Sound Absorption ◽  
Noise Control

Development of Natural Fibre Non-Woven Materials’ Application as Car Interiors for Noise Reduction

2011 ◽  
Vol 332-334 ◽  
pp. 1531-1534 ◽  
Author(s):  
Ming Ma ◽  
Yuan Bai ◽  
Xiao Ming Qian
Keyword(s):  
Noise Reduction ◽  
Reference Point ◽  
Sound Absorption ◽  
Noise Control ◽  
Natural Fibre ◽  
Noise Sources ◽  
Absorption Properties ◽  
Vehicle Noise ◽  
Nonwoven Materials ◽  
Potential Market

This document mainly introduces the evaluation of vehicle noise, noise sources and noise control. The development of fibers used for noise reduction materials is described as well. Besides, it analyzes the advantages and the necessities of the natural fibre nonwoven materials applied for the noise control, illustrates the present research status and the factors that introduces the sound absorption properties of the natural fibre nonwoven composites used for noise reduction. The paper also gives some reference point for advice to the development of automotive nonwoven materials. it shows that natural fibre nonwoven materials have a huge potential market and worthy for scholars to make a further study.

Research and Application of Building Enclosing Structure Used in Equipment Noise Control

2013 ◽  
Vol 423-426 ◽  
pp. 1272-1278
Author(s):  
Nan Xu
Keyword(s):  
Porous Material ◽  
Sound Absorption ◽  
Noise Control ◽  
Building Envelope ◽  
Sound Insulation ◽  
Hard Material ◽  
Noise Elimination ◽  
Control Engineering ◽  
Airborne Sound ◽  
Properties Of Materials

Porous material has a function of sound absorption, dense hard material can prevent the spread of airborne sound. The building envelope which is made up of different properties of materials, with good effects on sound insulation, sound absorption and noise elimination, can be widely used in noise control engineering.

Hybrid Active and Passive Noise Control of Cavities

2011 ◽  
Vol 97 (5) ◽  
pp. 752-760 ◽  
Author(s):  
Lenin Babu ◽  
Chandramouli Padmanabhan
Keyword(s):  
Porous Material ◽  
Elastic Material ◽  
Sound Absorption ◽  
Noise Suppression ◽  
Noise Control ◽  
Active Noise Control ◽  
Elastic Materials ◽  
Active Noise ◽  
Absorption Performance ◽  
Passive Noise

In this paper a hybrid active noise control of a cavity with poro-elastic material has been investigated. It has been found that the noise reduction achieved with active noise control in the cavity without poro-elastic material is not significantly altered with the presence of poro-elastic materials. This is shown to be independent of the porous material and its thickness and is true both at lower and mid-frequency ranges. Further, it is seen that macro perforations do not alter the sound absorption performance of the poro-elastic material in the presence of active noise control. The results clearly indicate that one can choose a smaller thickness of the porous material when active noise control is used in a cavity for noise suppression.

scholarly journals Design and simulation of multilayer hybrid foam material for acoustic application

2021 ◽  
Vol 12 ◽  
pp. 10
Author(s):  
L. Yuvaraj ◽  
S. Jeyanthi ◽  
Lenin Babu Mailan Chinnapandi ◽  
Elammaran Jayamani
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Noise Control ◽  
Numerical Study ◽  
Characteristic Impedance ◽  
Sound Absorption Coefficient ◽  
Metallic Foam ◽  
Polymeric Foam ◽  
Closed Cell ◽  
The Individual

New acoustic multilayer absorber fabricated by coupling closed-cell metallic foam and open-cell polymeric foam, which aimed to develop a practical use of metallic foam in the noise control application. In prior, the individual sound absorption coefficient of both foam materials with different thicknesses measured by the impedance tube method as per ASTM E-1050. Using inverse characterization technique, the intrinsic properties needed for five parameter models in a numerical study are predicted. The measured characteristic impedance, complex wave propagation, and sound absorption coefficient of the individual foams are in close agreement with the prediction. Subsequently, a different configuration of multilayer absorber is modeled using obtained properties, and their acoustic performance is evaluated. The result indicates that the coupling of polymeric foam with metallic one exhibits enhanced sound absorption and usage of closed-cell metallic foam in noise control material. Furthermore, the result demonstrates that absorption capability entirely relies on the placement of polymeric foam in the configuration. The proposed hybrid multilayer absorber coupled with test bench car for interior acoustic study, where 5–30 dB is reduction is noticed in 1/3rd octave plot.

scholarly journals Palm Oil Clinker As Noise Control Materials

2021 ◽  
Author(s):  
Zaiton Haron ◽  
Suhaida Ghalip ◽  
Khairulzan Yahya ◽  
Nadirah Darus ◽  
Herni Halim ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Absorption Coefficient ◽  
Palm Oil ◽  
Sound Absorption ◽  
Noise Control ◽  
Total Porosity ◽  
River Sand ◽  
Good Relationship ◽  
Good Strength ◽  
Concrete Properties

Palm oil clinker (POC) is a waste from the production process of palm oil, a hard and porous materials. Many studies have focused on the effect of POC use on strength while this study discusses the ability of POC in concrete to absorb sound and its relationship with concrete properties. The study was done by replacing natural river sand in stages of 25, 50, 75 and 100 percent in a mixture of 1: 4 (cement: sand). Sound absorption coefficient (SAC), strength and physical properties affect the SAC were measured. Although POC significantly reduced the compressive strength but all specimens poses good strength more than 5 N/mm2. An interesting result is that POC reduces interconnected porosity and total porosity when replacement is 100% but increases interconnected and total porosity when replacement is between 50 and 75%. SAC at 315 Hz was found has good relationship with percentage of POC and density. It is obtained that POC 50% yield good strength and sufficient SAC that can address the middle frequency range problem, thus can be further suggested to be used for masonry block application for noise control materials.

scholarly journals The Effect of Different Fibre Length and Different Urea Formaldehyde (UF) content on Sound Absorption Performance of Empty Fruit Bunch (EFB)

2018 ◽  
Vol 150 ◽  
pp. 03003
Author(s):  
Ida Norfaslia Nasidi ◽  
Lokman Hakim Ismail ◽  
Emedya Murniwaty Samsudin ◽  
Muhamad Firdaus Abdul Khodir ◽  
Muhammad Aizat Kamarozaman
Keyword(s):  
Sound Absorption ◽  
Noise Control ◽  
Urea Formaldehyde ◽  
Fibre Length ◽  
Binder Content ◽  
Empty Fruit Bunch ◽  
Optimum Amount ◽  
Sound Absorber ◽  
Fibre Size ◽  
Alternative Material

Noise control is part of the major requirements to improve the living environment. One of the best methods to reduce noise is by employing sound absorber material into a space. Since traditional sound absorber in the market was believed could cause health problems to human, the need for alternative material is desired. This research intended to utilize waste materials from palm oil empty fruit bunch (EFB) in the production of natural sound absorber for noise control in building. Two parameters were investigated; the fibre length and binder content to determine their effect on sound absorption. Samples were tested using impedance tube using low and high frequencies according to ISO 10534-2:2001. Consequently, both parameters show that different fibre length and binder content affected the ability of the fibre to absorb sound. Results show that the optimum fibre size is in between 2mm to 5mm length while the optimum amount of binder is between 0% to 5% and 15% from fibre weight. This research has found that the highest Noise Reduction Coefficient (NRC) using 2mm to 5mm fibre size achieved 0.70 coefficients while the use of optimum amount of binder (particularly Urea Formaldehyde) could obtain 0.75 NRC. The newly develop panels are considered as a good sound absorbent and suitable to use as an alternative material replacing the synthetic absorber.

Study on Sound Insulation Performance of Pressure Relief Wall of Transformer Chamber

2021 ◽  
Vol 263 (1) ◽  
pp. 5197-5202
Author(s):  
Fabing Rong ◽  
Zhongjie Cheng ◽  
Peijie Liu
Keyword(s):  
Noise Reduction ◽  
Sound Absorption ◽  
Vibration Isolation ◽  
Noise Control ◽  
Sound Insulation ◽  
Noise Emission ◽  
Pressure Relief ◽  
Actual Case ◽  
Noise Interference ◽  
Insulation Performance

The problem of noise nuisance in indoor substation becomes more and more sensitive. The noise emission index of substation has become an important technical index of substation design. The noise control of indoor substation mainly adopts "auxiliary noise reduction technology" such as sound absorption, sound insulation and vibration isolation. The sound insulation performance of the pressure relief wall in the main transformer room of indoor substation is the key link of noise control. In order to reduce the noise interference, this paper selects the common sound insulation structure of the pressure relief wall, analyzes the main influencing factors of noise reduction, selects the sound insulation structure suitable for the pressure relief wall in the main transformer room of indoor substation, and tests the effectiveness of noise reduction of the sound insulation structure in the actual case. Based on the research results, the sound absorption structure in the main transformer room is arranged on the other indoor wall outside the pressure relief wall, and the pressure relief wall mainly considers the structure of sound insulation, which can effectively reduce the noise impact of the main transformer room.

Preparation and Sound Absorption Property of Al-Si12 Alloy Foam Core Muffler

2011 ◽  
Vol 183-185 ◽  
pp. 1687-1691 ◽  
Author(s):  
Ying Wu Wang ◽  
Xiao Qing Zuo ◽  
Xian Ning Chen
Keyword(s):  
Sound Absorption ◽  
Pore Diameter ◽  
Noise Control ◽  
Foam Core ◽  
Absorption Property ◽  
Filtration Method ◽  
Diameter Range ◽  
Absorbing Materials

Al-Si12 alloy foams were fabricated by filtration method, and the Al-Si12 alloy foam core mufflers were made by using the fabricated Al-Si12 alloy foams. The preparation and sound absorption property of Al-Si12 alloy foam core muffler has been studied. The results show that sound absorption property of Al-Si12 alloy foam core muffler increases with the decreasing of pore diameter and the widening of the pore diameter range of Al-Si12 alloy foam core. Being superior to conventional sound-absorbing materials core mufflers, Al-Si12 alloy foam core muffler especially fits in noise control in hot, wet, and open-air environments.

Sign in / Sign up

Export Citation Format

Share Document