Noise Canceling
February 16, 2007 In an interesting development, the same technology that is used in noise-cancelling headphones (roughly speaking) is to be applied to heavy marine engines to reduce their noise and vibrations. The vibrations from marine diesels spreads through the entire hull, but researchers have now found a way of blocking the sound immediately below the engine with the help of computer-controlled counter-vibrations from an active damper between the engine and the bearing by which the engine is attached to the hull. This active bearing is made primarily from piezo-ceramics, materials that can change their shape when electrically stimulated. If they are stimulated very quickly, they generate high-frequency vibrations – which are exactly what marine engines need. Using sophisticated sensors, the scientists measure the engine’s vibrations and trigger the piezo-ceramics such that they precisely counteract this motion. Read More
December 8. 2006 Quellan today announced the extension of its innovative Wideband noise cancellation technology to mobile handsets and consumer devices. Successfully used in data center applications to improve the crosstalk, speed and reach of interconnects, these smaller and lower power consumer devices reduce noise in wireless handsets, laptop computers and game consoles. Unlike filters, these devices cancel wideband noise in the receivers' input spectrum. By dropping the noise floor at the receivers input, a substantial improvement in signal-to-noise ratio is achieved, resulting in fewer dropped calls, continuous video capability and GPS location locks in high density urban areas. Read More
