noise absorbing Articles

  • Simulation tool for shock absorber noise prediction in time and frequency domains

    This paper investigates the validity of a hydraulic simulation model to calculate the piston rod acceleration for further frequency domain analysis. At the present time, simulation results analyses of shock absorber characteristics are mostly restricted to the low frequency range for the hydraulic behaviour and the high frequency range for Noise, Vibration and Harshness (NVH) studies. However ...


    By Inderscience Publishers

  • Tackling Office Noise – The Sound Investment

    Open offices or shared offices can offer great benefits in terms of communication but they can also present challenges. We’ve all had problems with noise in the office - the incessant chatter of your colleagues ruining your concentration; people shouting over you when you are trying to have a conversation on the phone; perhaps even maintenance or construction work going on next door. ...


    By Pulsar Instruments plc

  • Reducing noise levels through engineering controls

      It"s fairly easy to control personal exposure to noise by limiting exposure time or using hearing protectors like ear plugs or ear muffs.  Engineering controls are usually applied to the machinery that produces noise. Imagine a 200 foot x 175 foot manufacturing facility with a 30 foot high ceiling.  In this building are a variety of cut-off saws, grinders, millers and other ...

  • Accurate and efficient prediction of acoustical performance of noise barriers against transport noise pollution

    An improved acoustical wave propagator (I_AWP) technique with high-order absorbing boundary technique is introduced to evaluate the acoustical wave interaction for noise barriers, providing the dual benefit of preserving high numerical accuracy (boundary conditions have been properly treated) and obtaining high computational efficiency (using a larger time step in the calculation). The aim is to ...


    By Inderscience Publishers

  • Canarina CUSTIC software · noise impact assessments · introduction 1

    Our planet is fragile and limited as for its potential of generating the resources that the humanity requests and its capacity to absorb the residuals that we emit. The precariousness of the ecological and environmental resistance of the earth can end up threatening the humanity's development. IUICN, PNUMA, WWF and Agenda 21 plead insistently to reach the ...

  • Acoustiblok® Quiets Well Motor Noise for California Water District

    Acoustiblok recently resolved a noisy well motor issue that was affecting some nearby residents for Three Valleys Municipal Water District (Three Valleys MWD) in California. Ben Peralta, a Three Valleys MWD engineer working on the project said, “The new Acoustiblok All Weather Sound Panels perform better than the old ...


    By Acoustiblok International

  • Bespoke noise protection: AERZEN relies on the advantages of reactive silencers

    With reactive silencers, AERZEN reduces the noise emissions on the discharge side of its screw compressors, positive displacement blowers, and rotary lobe compressors. The innovative concept of these reactive silencers is superior to classic dissipative silencers in many respects. The sound waves developing on the discharge side of a Delta Screw compressor made by AERZEN can reach 170 to 190 dB. ...

  • Case study - Nor848A Acoustic Camera Metro station in Taipei, Taiwan

    After the construction of the elevated sky train, too high noise levels were appearing under the line and local communities were complaining. Therefore acoustic absorbing panels were mounted under the metro line at critical sites in order to reduce noise emission. To document the effect of the absorbers a Norsonic Nor848A 1.0 meter acoustic camera was setup for recording and reporting on the ...


    By Norsonic AS

  • Dissipative expansion chambers with two concentric layers of fibrous material

    The acoustic performance of a dissipative expansion chamber lined with two concentric, annular layers of fibrous material with different resistances is investigated. A two-dimensional analytical approach is used to determine the transmission loss of this dissipative silencer. From the boundary conditions at the rigid wall, and the interfaces between the fibre layers and the central airway, the ...


    By Inderscience Publishers

  • What is an anechoic chamber and how quiet can it be?

    One of the things that we often talk about when we’re running our CPTC (Cirrus Product Training Courses) is how our hearing works and we often end up talking about how, if there’s no ambient sound, we can feel uncomfortable and can become disoriented very quickly. One of the best (or maybe the worst) places to experience this is in ...


    By Cirrus Research plc

  • Sound field diffusivity at the top surface of schroeder diffuser barriers

    It has been shown in several studies that the T-shape profile barriers are one of the most successful noise barriers among many different profiles (May and Osman 1980; Hajek and Blaney 1984; Hothersall et al., 1991). In this case, it is shown by author (Monazzam and Lam, 2005) that in the same dimension, the T-shape profile has the highest performance compared to other profiled noise barriers. It ...


    By University of Tehran

  • Active leakage control in low pressures - It can be done!

    Leakage and PressureWater when leaving the pipe creates an ‘energy’ and it is this energy that is transferred through the water and the pipe wall by the means of acoustic sound. This acoustic sound depending on the material of the pipe work either dissipates over a long distance or is absorbed very quickly into the pipe wall. The effect being that for metallic or hard walled pipes the sound ...


  • Case study - Filming sound leakages in highly reflective office environment

    Problem A newly built office complex is designed with glass facades between the offices and the hallway. The glass facades include a glass door. Although the glass structures themselves have a sufficient sound reduction value, the sound insulation between office and hallway was measured at 19 dB, which was far below the sound insulation criteria for offices given in the regulations. It ...


    By Norsonic AS

  • Engine Testing

    Engine testing involves measurement of rotating speed and torque of the engine by applying load controlled by a dynamometer connected to its output shaft. HORIBA has developed various types of dynamometer for the purpose of engine testing. They are mainly classified into two types; one is absorbing only dynamometer such as hydraulic dynamometers and eddy-current dynamometers, the other is ...


    By HORIBA Europe GmbH

  • How big should urban green spaces be?

    With cities poised to add 2.5 billion more people by 2050, now is a perfect time to get strategic about urban design. One of the big questions planners face is the best way to accommodate both built environments and natural settings, which provide important services such as making oxygen, cleansing water, absorbing noise, ...


    By Ensia

  • Opinion: The city: environmental issues and sustainable development

    The city with which I am most familiar is Greater London. The crucial environmental issues for London have been benchmarked in the Mayor’s State of the Environment Report for London (May 2003) as required by the Greater London Authority Act 1999. It covers the following issues, which are probably applicable to a lesser or greater extent to any metropolis: land quality and the conservation of ...


  • Chlorine gas protection - Case Study

    Application As part of a scheme to bring safe drinking water to 1.5 million people in Omdurman City, part of Greater Khartoum, Biwater International was appointed by the Government of Sudan to undertake a major turnkey design and construction project. Chlorine is the conventional means of water disinfection, so Biwater brought in ERG to design and manufacture the emergency gas ...

  • HORIBA Mechatronics Product Lines

    HORIBA has several decades of experience in providing solutions for automotive test systems. We have focused on testing components of the vehicle powertrain including the engine, transmission, clutch, torque converter, axles or brakes up to the complete vehicle. In all cases the missing parts of the vehicle and its environment is replaced by a system able to reproduce the load the specimen would ...


    By HORIBA Europe GmbH

  • Beer`s law

    The Beer-Lambert relationship (or Beer's law) states that the concentration C is directly proportional to the absorbance A. Generally, this relationship is more often applied by comparing the height of a maximum absorption peak of a reference gas to the height of the corresponding peak in a sample spectrum. However, this technique suffers if the baseline is not accurately known, and it fails ...


    By CIC Photonics, Inc.

  • 50th anniversary of world`s first sound level meter

    Sound Level Meter Celebrates 50th Anniversary 2010 is the year we celebrate the 50th anniversary of Type 2203, the mother of all sound level meters. It was the world’s first precision hand-held and transitorised sound level meter. Produced for 21 years, it sold a record number of 17300 units. With its upgrades Type 2204 (Impulse time constant) and 2209 (peak detector), it accounted for a ...

Need help finding the right suppliers? Try XPRT Sourcing. Let the XPRTs do the work for you