21st-century acoustic control science/engineering

May 16, 2011 - 12:39am

hollowman

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21st-century acoustic control science/engineering

May 16, 2011 - 12:54am

hollowman

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Quote:

Anechoic chambers are designed to be acoustically perfect. No sound reflects from the walls, floor or ceiling, and they are insulated from exterior noise. Because of this they are ideal places to test loudspeakers or microphones and for virtual acoustics – the recreation of concert hall, city street and other spaces' acoustics.

In 2004, the Guinness Book of World Records proclaimed the anechoic chamber at Orfield Laboratories in Minneapolis, Minnesota, the quietest place on Earth. It was measured at -9.4 decibels. The decibel unit describes a ratio of sound pressure and the standard reference level is set at the sensitivity of the human ear, so a negative level means a sound has a pressure too small to hear – to us, this would seem like absolute silence.

http://www.newscientist.com/gallery/sonic-doom-noise-in-pictures/6

May 16, 2011 - 12:59am

hollowman

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WTF is that? The latest from Michael Green Audio? Or Illbruck? Not really ...

http://www.newscientist.com/gallery/sonic-doom-noise-in-pictures/5

Phononic future

This sculpture by Eusebio Sempere, entitled Órgano, is an example of a phononic crystal, potentially the future of sound-proofing.

Phononic crystals are created by arranging elements, in this case metal pipes, to control the flow of sound. The position and size of these elements prevent selected frequencies from being transmitted through the material. When researchers from the Institute of Materials Science in Madrid, Spain, tested the acoustic properties ofÓrgano 18 years after its creation, they found it made a good phononic crystal.

Research is now under way at the UK'sTransport Research Laboratory to see if modified structures like this can be used to cut noise along roads and railways.