Down with noise

Article Abstract:

New digital signal processing technology is being used for active noise control to make passenger cabins quieter and get rid of sounds that disrupt headset communication. Destructive interference can be set up between two sound fields according to Stephen J. Elliott, professor, Inst. of Sound and Vibration Research, University of Southampton, UK. When two sounds fields can be accurately aligned over an acoustic wavelength in space the technique is most effective. Advances in digital signal-processing (DSP) chips have made such efforts practical. Control of tonal noise is far easier than control of random noise and it is not likely that all noise problems can be solved. In the process control community the best known system is internal model control (IMC). Headsets that cut noise are made for military use by Racal Acoustics Ltd. of the UK, Lectret Precision, Singapore, and Bose, Framingham, MA. Other companies whose products are discussed included, NCT Group, Sony, Sennheiser Electronic GmbH, Lord Corp. and Ultra Electronics.

United States, Semiconductors and related devices, Semiconductor and Related Device Manufacturing, Research and Development in the Physical, Engineering, and Life Sciences, Household audio and video equipment, Audio and Video Equipment Manufacturing, Science & research, Other Communications Equipment Manufacturing, Guided Missile and Space Vehicle Manufacturing, Blowers and fans, Air Purification Equipment Manufacturing, Digital Signal Processing Equip, Headphones, Guided Missiles, Space Vehicles, Parts, Missiles, Space Vehicles & Parts, Integrated Circuits by Function, Air Pollution Noise Control Eqp, Noise Abatement R&D, Semiconductor industry, Usage, Product development, Integrated circuits, Equipment and supplies, Airlines, Electronics industry, Industrial equipment and supplies industry, Industrial equipment industry, Audio equipment industry, Aerospace industry, Noise control, Pollution control research, Application specific integrated circuits, Pollution control equipment, Digital signal processors, Military vehicles, Vehicles, Military, Noise control equipment

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Exploring the third dimension

Article Abstract:

The features of the 3Dconnexion's SpaceNavigator, which is useful in computer aided design of the product, are presented.

Prepackaged software, Computer software industry, Software industry, Product information, CASE software, 3Dconnexion, SpaceNavigator (CASE software)

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