Acoustic Monitoring Articles

  • Acoustic camera and beampattern

    Abstract—The wavenumber-frequency response of an array describes the response to an arbitrary plane wave both in time and space. When the input consists of a single monochromatic plane wave, the response of the array is referred to as the array pattern or beampattern. Through the design of the array our goal is to have a directivity of the array as high as possible in a given direction, ...


    By Norsonic AS

  • City Of Vancouver Deploys Free-Swimming Tools For Successful Inline Inspection Of Pressurized Main

    With its Pacific Ocean entranceway and towering backdrop of snow-dusted mountains, it’s no wonder the City of Vancouver ranks among the most laid-back, beautiful cities in Canada, and indeed, the world. Water is in its blood. This spring the coastal seaport city retained the services of ...

  • Case study - Wall leakage testing in the lab with acoustic camera

    Problem Facade insulation testing is usually performed by using a loudspeaker in the sending room, and record the sound pressure level (SPL) with microphones in both the sending and receiving room. The difference in SPL adjusted for the size of the dividing wall element will then give an estimate of the sound reduction quality of that element. However these measurements will not say ...


    By Norsonic AS

  • Case study - Using acoustic camera inside caravan car to find squeak and rattle noise

    Problem When driving a caravan car, the driver could hear annoying noises from behind the driver’s cab in the living compartment. Even though the noises could be heard clearly, it was very difficult to discover the exact location and cause of the various annoying sounds due to overwhelming background noise. When the car was standing still with the engine running, no extra ...


    By Norsonic AS

  • Case study - Filming low-frequency structure born noise with acoustic camera

    Problem An apartment complex consists of five floors, with several apartments over four floors, and an attic on the top floor. In the attic an air circulation system is installed to provide circulation in the bathroms of all the apartments in the building. The circulation system is driven by an air fan distributing air through pipes going to all apartments. The air pipes are cemented in ...


    By Norsonic AS

  • Case study - Pinpointing low level sanitary noise in apartment building

    Problem A newly built apartment building consists of several floors with multiple apartments on each floor. One of the ground floor apartments is disturbed by sanitary noise from the apartment above, which is heard whenever the toilets in the top apartment are being flushed. The sanitary noise is heard in several rooms, and the level was measured to be around 30 to 35 dB, which is above ...


    By Norsonic AS

  • Numbers don’t Lie, PCCP performance and deterioration based on a statistical review of a decade of condition assessment data

    Abstract Since the late 1990s there have been numerous inspection and monitoring projects focused on identifying and quantifying wire break damage in PCCP water and wastewater pressure mains. The pressing need to identify and manage deterioration of PCCP has resulted in the rapid development of a small but highly focused niche industry of condition assessment of PCCP mains. During this ...

  • Case study - Finding acoustical weak points in room dividing modular walls

    Problem A conference hotel is using modular walls to divide large halls into several smaller conference rooms. The rooms are divided by modular walls that provide several different opportunities for subdivision and multipurpose use of the large area spaces. When measuring the sound insulation between adjacent rooms through the modular walls, the resulting value was found to be too ...


    By Norsonic AS

  • Case study - Identifying low-frequency tonal noise in windy and noisy conditions

    Problem A large LNG gas facility (approximately 300m x 150m) producing 300 000 tons of LNG annually is situated in a terminal area with the nearest populated area at a distance of around 1 km. Within the gas production facility, a low-frequency tonal noise at around 500 Hz is generated causing complaints from nearby neighbours. The tone imposes a more stringent noise requirement on the ...


    By Norsonic AS

  • PAMBuoy:Monitoring Beluga Whales in Alaska case study

    Real-time monitoring for beluga whales (Delphinapterus leucas) in the Eagle River, Alaska using a PAMBuoy detection system Real time monitoring for beluga whales (Delphinapterus leucas) in the Eagle River, Alaskausing a PAMBuoy detection system. Final Contract Report by SMRU, LLC and Marine Instruments Ltd. 19p. The Army and Air Force teamed with the Alaska Department of Fish and Game ...

  • 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

  • New mandatory acoustic testing in UK schools

    As a result of campaigning by the National Deaf Children’s Society,The Department for Children, Schools and Families, has recently announced a set of guidelines to improve acoustics in schools in England and Wales. Whilst acoustic standards in schools have been regulated by Building Bulletin 93 (BB93) since 2003, there is currently no mandatory requirement for pre-completion testing to ...

  • Robots reduce test setup by 90%

    Konica Minolta Business Technologies Inc.’s newly established acoustic test laboratory has world-class acoustic features and equipment. Brüel & Kjær contributed with a turnkey PULSE solution including the supply of a microphone positioning robot with computer control for the automatic determination of sound power. Setting up for a test used to take 45 minutes but, as a result ...

  • Vibro-acoustic analysis of functionally graded circular discs under thermal environment

    A circular disc made up of Functionally Graded Material (FGM) with several cases of FGM index are modelled and their vibration response to a harmonic point load in a thermal environment with temperature dependant material properties was computed by using the Finite Element Method (FEM). A macro was developed by the corresponding author in ANSYS Parametric Design Language for modelling FGM using ...


    By Inderscience Publishers

  • National Aerospace Laboratories (CSIR) – celebrating 50 years of excellence

    National Aerospace Laboratories (NAL), Bangalore is a constituent of the Council of Scientific and Industrial Research of India (CSIR). Originally started as National Aeronautical Laboratory, it was renamed National Aerospace Laboratories to reflect its major involvement in the Indian space programme, its multidisciplinary activities and it’s global positioning. Over the last five decades ...

  • Putting the surface microphone through its paces at Airbus

    Thirty-odd years later, the A380 – the widest commercial airliner available today with seating for 525 passengers – will be entering into service. It is another testament to Airbus’ commitment to innovation and intelligent design. Therefore, Airbus came to Brüel & Kjær for the development of a transducer they could invariably use to measure sound pressure in ...

  • Case study - Man-Made River Authority (MRA)

    Service: SoundPrint® AFO Client: Man-Made River Authority Project Date: Ongoing since 2004 Location: Ajdabiya, Libya Type of Pipelines: Raw Water Transmission Mains Diameter: 158-inch (4 meter) Pipe Material: PCCP Length: 1,200 km Results: 35,000 wire breaks as of 2011 Libya's Man Made River With more than 4,000 km of mainly four-metre diameter ...

  • Case study - Fred Hartman Bridge - Harris County, Texas

    Service: SoundPrint - Bridges Client: Texas Department of Transportation (TxDOT) Project Date: 2002 Type of Bridge: Fan arranged cable-stayed bridge Length: 4.185 kilometres (2.60 mi) The Fred Hartman Bridge was opened to traffic in 1995 and is one of the largest cable stayed bridges in the United States. The cable stayed bridge portion of the bridge ...

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