noise propagation Articles

  • Environmental Noise (Booklet)

    About this booklet This booklet deals with environmental noise − for example, noise from industrial sites, road and rail traffic, airports and fairgrounds. It does not cover related issues such as building acoustics, building vibration or domestic noise. Neither does it cover human response to vibration nor industrial uses of sound and vibration measurements. Please contact ...

  • Using neural networks to identify annoying noises in vehicles

    Previous papers have developed a methodology to characterise squeaks and rattles. Thus, for each noise, its origin and the means for eliminating it, are known. This paper describes the work done towards the development of a tool, based on neural networks, that determines if a squeak or rattle corresponds to any of the noises already characterised. Different types of neural networks have been ...


    By Inderscience Publishers

  • 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

  • Short-term noise monitoring with DELTA - Case Study

    Acoustical expert, DELTA expanded its noise measurement capabilities by subscribing to Bruel & Kjaer's Noise Sentinel On Demand service. DELTA - one of the leading acoustical consultant companies in Denmark - accepted a project to measure airport noise. Making actual noise measurements and calculating how changes in air traffic affect the propagation of noise can be time consuming ...

  • Clutching At Straws to Come Up With Noise Level Solution

    The UK is renowned for its rich heritage in hosting outdoor festivals, whether it be music or literary, through to farming, food or catering to even more niche audiences. But every festival is unique and, no matter how large or small, they bring with them their own issues when it comes to health & safety and noise related ...


    By Cirrus Environmental

  • Noise Calculation Software noise3D online Release 2

    Sankt Augustin, Germany – Sonja Christiansen Informatk GmbH is announcing Release 2.0 of the web enabled noise calculation solution noise 3D online™, a first in 3D noise prediction online services. If you need to predict or map noise levels in the industrial environment and require an affordable tool noise 3D online may be the solution. ...


  • New Environmental Noise Measurement Workshop from Cirrus

    We’re pleased to announce the launch of a new 1-day Environmental Noise Measurement Workshop, aimed at any professional requiring either an introduction to or a refreshment of the principles of environmental noise measurement. This one-day event that has been designed to give attendees an overview of Environmental Noise Measurement. This will cover the basics of sound, the ...


    By Cirrus Research plc

  • Canarina CUSTIC software · noise pollution modeling · algorithms 1

    8. Mathematical algorithms   The mathematical model that the software uses provides options to model noise emissions from a wide range of sources that might be present at industrial areas and urban areas.   The basis of the model is the linear sound propagation  equation, which is used to model simple point source emissions from vehicles, industries, aircrafts,… ...

  • On the application of partial barriers for spinning machine noise control: A theoretical and experimental approach

    Noise reduction by barriers is a popular measure for environmental protection in both urban and rural areas. A barrier, which intercepts the direct path of sound from source to receiver, is frequently used to protect noise sensitive receivers from land transportation noise radiating from highways, railway lines, industrial complexes and airports. This consists of interposing a heavy non-porous or ...


    By University of Tehran

  • Canarina CUSTIC software · environmental noise modeling · algorithms 4

    In the railway case, we shall calculate the noise level in a similar way. For airports, we shall use the next equation Leq=Leq(300m)-20Log(r/300) where Leq(300m) is the noise level at 300m from the airport. This model performs satisfactorily for simple sound ...

  • Investigation into noise problems in vehicle structure using vibro-acoustic approach

    The main focus of this paper is the study of the relationship between components of vibration and noise inside the passenger cabin of a production vehicle. The noise inside automobiles is largely composed of contributions from the engine, ground and wind. The engine and tyres successively transfer the vibration via the structural connections to the body panels, which then propagates through the ...


    By Inderscience Publishers

  • Noise Planning Software Used to Map Major EU Roadways

    Most countries have a national noise policy to protect citizens from undesirable environmental noise levels from road, rail and air traffic and industrial sources. The European Noise Directive for the Assessment and Management of Environmental Noise outlines a coordinated method to achieve noise reduction in large cities as a first step, followed by smaller cities as a second step. The ...


    By SoundPLAN International LLC

  • Experimental investigation of power-assisted steering pump noise for housing material change from cast iron to aluminium

    Noise and vibration have an important influence on a customer's perception of vehicle quality. In this research, the major power-assisted steering pump noise propagation mechanism is determined. Noise and vibration comparison tests have been completed for subjectively good and bad cast-iron housed pumps, as well as for an aluminium housed pump. Decoupling tests for the steering rack disconnected ...


    By Inderscience Publishers

  • Vibration attenuation of automotive vehicle engine using periodic mounts

    In this paper, a new class of periodic mounts for isolating the vibration transmission from vehicle engine to the car body and seats is presented. Periodic mounts exhibit unique dynamic characteristics that make them act as mechanical filters for wave propagation. As a result, waves can propagate along the periodic mounts only within specific frequency bands called the 'Pass Bands' and wave ...


    By Inderscience Publishers

  • 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

  • A computational fluid dynamics study of crosswind effects on vehicle A–pillar aero–acoustics

    The surface pressure fluctuations due to the flow separation in the A–pillar region on the front side windows of a passenger car is a dominant source of aerodynamic noise. Aerodynamically generated noise adversely affects vehicle occupant's comfort and safety (due to fatigue caused by long time noise exposure). The size and magnitude of the A–pillar flow separation mainly depend on the local ...


    By Inderscience Publishers

  • Canarina CUSTIC software · Environmental standard · commands 22

    Noise power (dB): This is the noise power at source position in decibels.   Airport options: We have two options: An aircraft landing/taking off at 300m or Daily average (number of airport operations in a day). ...

  • Predicting acoustic transmission loss through laminated glass with air and porous layers

    This study analyses the sound transmission characteristic of various laminated glass designs with application to motor vehicles. The porous interlayer in the laminated glass is filled with polyvinyl butyral (PVB) that serves as an acoustic damper. To model the physics behind the sound transmission losses of the fluid, solid and porous layers, acoustic noise transfer matrices are used to relate ...


    By Inderscience Publishers

  • Case study - Use of the Nor848A acoustic camera on wind turbines

    The acoustic camera system Nor848 is a powerful tool to investigate noise sources. In realtime you listen to a beamformed audio signal so that you can hear individual sources one by one. Immediately you can identify the strongest over all noise source in a multisource environment, and you can do the same analysis for single frequencies, 1/3 or 1/1 octave bands or any given frequency range. This ...


    By Norsonic AS

  • Improving activated sludge classification based on imbalanced data

    A fast and accurate classification method for sewage sludge biological activity classification is of great significance for wastewater treatment. However, the data are often imbalanced and the accuracy of traditional classification algorithms applied to imbalanced small classes of data is very low. Such small classes are crucial application data. Therefore, based on the analysis of eight ...


    By IWA Publishing

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